1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Support for tracepoints on aarch64-linux was added in GDBserver.
8 * The 'record instruction-history' command now indicates speculative execution
9 when using the Intel(R) Processor Trace recording format.
11 * GDB now allows users to specify explicit locations, bypassing
12 the linespec parser. This feature is also available to GDB/MI
17 maint set target-non-stop (on|off|auto)
18 maint show target-non-stop
19 Control whether GDB targets always operate in non-stop mode even if
20 "set non-stop" is "off". The default is "auto", meaning non-stop
21 mode is enabled if supported by the target.
24 maint show bfd-sharing
25 Control the reuse of bfd objects.
29 Control display of debugging info regarding bfd caching.
31 * The "disassemble" command accepts a new modifier: /s.
32 It prints mixed source+disassembly like /m with two differences:
33 - disassembled instructions are now printed in program order, and
34 - and source for all relevant files is now printed.
35 The "/m" option is now considered deprecated: its "source-centric"
36 output hasn't proved useful in practice.
38 * Support for various ROM monitors has been removed:
40 target dbug dBUG ROM monitor for Motorola ColdFire
41 target picobug Motorola picobug monitor
42 target dink32 DINK32 ROM monitor for PowerPC
43 target m32r Renesas M32R/D ROM monitor
44 target mon2000 mon2000 ROM monitor
45 target ppcbug PPCBUG ROM monitor for PowerPC
47 *** Changes in GDB 7.10
49 * Support for process record-replay and reverse debugging on aarch64*-linux*
50 targets has been added. GDB now supports recording of A64 instruction set
51 including advance SIMD instructions.
53 * Support for Sun's version of the "stabs" debug file format has been removed.
55 * GDB now honors the content of the file /proc/PID/coredump_filter
56 (PID is the process ID) on GNU/Linux systems. This file can be used
57 to specify the types of memory mappings that will be included in a
58 corefile. For more information, please refer to the manual page of
59 "core(5)". GDB also has a new command: "set use-coredump-filter
60 on|off". It allows to set whether GDB will read the content of the
61 /proc/PID/coredump_filter file when generating a corefile.
63 * The "info os" command on GNU/Linux can now display information on
65 "info os cpus" Listing of all cpus/cores on the system
67 * GDB has two new commands: "set serial parity odd|even|none" and
68 "show serial parity". These allows to set or show parity for the
71 * The "info source" command now displays the producer string if it was
72 present in the debug info. This typically includes the compiler version
73 and may include things like its command line arguments.
75 * The "info dll", an alias of the "info sharedlibrary" command,
76 is now available on all platforms.
78 * Directory names supplied to the "set sysroot" commands may be
79 prefixed with "target:" to tell GDB to access shared libraries from
80 the target system, be it local or remote. This replaces the prefix
81 "remote:". The default sysroot has been changed from "" to
82 "target:". "remote:" is automatically converted to "target:" for
83 backward compatibility.
85 * The system root specified by "set sysroot" will be prepended to the
86 filename of the main executable (if reported to GDB as absolute by
87 the operating system) when starting processes remotely, and when
88 attaching to already-running local or remote processes.
90 * GDB now supports automatic location and retrieval of executable
91 files from remote targets. Remote debugging can now be initiated
92 using only a "target remote" or "target extended-remote" command
93 (no "set sysroot" or "file" commands are required). See "New remote
96 * The "dump" command now supports verilog hex format.
98 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
100 * On GNU/Linux, GDB and gdbserver are now able to access executable
101 and shared library files without a "set sysroot" command when
102 attaching to processes running in different mount namespaces from
103 the debugger. This makes it possible to attach to processes in
104 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
105 See "New remote packets" below.
107 * The "tui reg" command now provides completion for all of the
108 available register groups, including target specific groups.
110 * The HISTSIZE environment variable is no longer read when determining
111 the size of GDB's command history. GDB now instead reads the dedicated
112 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
113 disables truncation of command history. Non-numeric values of GDBHISTSIZE
118 ** Memory ports can now be unbuffered.
122 ** gdb.Objfile objects have a new attribute "username",
123 which is the name of the objfile as specified by the user,
124 without, for example, resolving symlinks.
125 ** You can now write frame unwinders in Python.
126 ** gdb.Type objects have a new method "optimized_out",
127 returning optimized out gdb.Value instance of this type.
128 ** gdb.Value objects have new methods "reference_value" and
129 "const_value" which return a reference to the value and a
130 "const" version of the value respectively.
134 maint print symbol-cache
135 Print the contents of the symbol cache.
137 maint print symbol-cache-statistics
138 Print statistics of symbol cache usage.
140 maint flush-symbol-cache
141 Flush the contents of the symbol cache.
143 maint set target-non-stop (on|off|auto)
144 maint show target-non-stop
145 Control whether GDB targets always operate in non-stop mode even if
146 "set non-stop" is "off". The default is "auto", meaning non-stop
147 mode is enabled if supported by the target.
151 Start branch trace recording using Branch Trace Store (BTS) format.
154 Evaluate expression by using the compiler and print result.
158 Explicit commands for enabling and disabling tui mode.
161 set mpx bound on i386 and amd64
162 Support for bound table investigation on Intel(R) MPX enabled applications.
166 Start branch trace recording using Intel(R) Processor Trace format.
169 Print information about branch tracing internals.
171 maint btrace packet-history
172 Print the raw branch tracing data.
174 maint btrace clear-packet-history
175 Discard the stored raw branch tracing data.
178 Discard all branch tracing data. It will be fetched and processed
179 anew by the next "record" command.
184 Renamed from "set debug dwarf2-die".
186 Renamed from "show debug dwarf2-die".
189 Renamed from "set debug dwarf2-read".
190 show debug dwarf-read
191 Renamed from "show debug dwarf2-read".
193 maint set dwarf always-disassemble
194 Renamed from "maint set dwarf2 always-disassemble".
195 maint show dwarf always-disassemble
196 Renamed from "maint show dwarf2 always-disassemble".
198 maint set dwarf max-cache-age
199 Renamed from "maint set dwarf2 max-cache-age".
200 maint show dwarf max-cache-age
201 Renamed from "maint show dwarf2 max-cache-age".
204 show debug dwarf-line
205 Control display of debugging info regarding DWARF line processing.
209 Set the maximum number of candidates to be considered during
210 completion. The default value is 200. This limit allows GDB
211 to avoid generating large completion lists, the computation of
212 which can cause the debugger to become temporarily unresponsive.
214 set history remove-duplicates
215 show history remove-duplicates
216 Control the removal of duplicate history entries.
218 maint set symbol-cache-size
219 maint show symbol-cache-size
220 Control the size of the symbol cache.
222 set|show record btrace bts buffer-size
223 Set and show the size of the ring buffer used for branch tracing in
225 The obtained size may differ from the requested size. Use "info
226 record" to see the obtained buffer size.
228 set debug linux-namespaces
229 show debug linux-namespaces
230 Control display of debugging info regarding Linux namespaces.
232 set|show record btrace pt buffer-size
233 Set and show the size of the ring buffer used for branch tracing in
234 Intel(R) Processor Trace format.
235 The obtained size may differ from the requested size. Use "info
236 record" to see the obtained buffer size.
238 maint set|show btrace pt skip-pad
239 Set and show whether PAD packets are skipped when computing the
242 * The command 'thread apply all' can now support new option '-ascending'
243 to call its specified command for all threads in ascending order.
245 * Python/Guile scripting
247 ** GDB now supports auto-loading of Python/Guile scripts contained in the
248 special section named `.debug_gdb_scripts'.
252 qXfer:btrace-conf:read
253 Return the branch trace configuration for the current thread.
255 Qbtrace-conf:bts:size
256 Set the requested ring buffer size for branch tracing in BTS format.
259 Enable Intel(R) Procesor Trace-based branch tracing for the current
260 process. The remote stub reports support for this packet to GDB's
264 Set the requested ring buffer size for branch tracing in Intel(R) Processor
268 Indicates a memory breakpoint instruction was executed, irrespective
269 of whether it was GDB that planted the breakpoint or the breakpoint
270 is hardcoded in the program. This is required for correct non-stop
274 Indicates the target stopped for a hardware breakpoint. This is
275 required for correct non-stop mode operation.
278 Return information about files on the remote system.
281 Return the full absolute name of the file that was executed to
282 create a process running on the remote system.
285 Select the filesystem on which vFile: operations with filename
286 arguments will operate. This is required for GDB to be able to
287 access files on remote targets where the remote stub does not
288 share a common filesystem with the inferior(s).
291 Indicates that a fork system call was executed.
294 Indicates that a vfork system call was executed.
296 vforkdone stop reason
297 Indicates that a vfork child of the specified process has executed
298 an exec or exit, allowing the vfork parent to resume execution.
300 fork-events and vfork-events features in qSupported
301 The qSupported packet allows GDB to request support for fork and
302 vfork events using new 'gdbfeatures' fork-events and vfork-events,
303 and the qSupported response can contain the corresponding
304 'stubfeatures'. Set and show commands can be used to display
305 whether these features are enabled.
307 * Extended-remote fork events
309 ** GDB now has support for fork events on extended-remote Linux
310 targets. For targets with Linux kernels 2.5.60 and later, this
311 enables follow-fork-mode and detach-on-fork for both fork and
312 vfork, as well as fork and vfork catchpoints.
314 * The info record command now shows the recording format and the
315 branch tracing configuration for the current thread when using
316 the btrace record target.
317 For the BTS format, it shows the ring buffer size.
319 * GDB now has support for DTrace USDT (Userland Static Defined
320 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
322 * GDB now supports access to vector registers on S/390 GNU/Linux
325 * Removed command line options
327 -xdb HP-UX XDB compatibility mode.
329 * Removed targets and native configurations
331 HP/PA running HP-UX hppa*-*-hpux*
332 Itanium running HP-UX ia64-*-hpux*
334 * New configure options
337 This configure option allows the user to build GDB with support for
338 Intel(R) Processor Trace (default: auto). This requires libipt.
340 --with-libipt-prefix=PATH
341 Specify the path to the version of libipt that GDB should use.
342 $PATH/include should contain the intel-pt.h header and
343 $PATH/lib should contain the libipt.so library.
345 *** Changes in GDB 7.9.1
349 ** Xmethods can now specify a result type.
351 *** Changes in GDB 7.9
353 * GDB now supports hardware watchpoints on x86 GNU Hurd.
357 ** You can now access frame registers from Python scripts.
358 ** New attribute 'producer' for gdb.Symtab objects.
359 ** gdb.Objfile objects have a new attribute "progspace",
360 which is the gdb.Progspace object of the containing program space.
361 ** gdb.Objfile objects have a new attribute "owner".
362 ** gdb.Objfile objects have a new attribute "build_id",
363 which is the build ID generated when the file was built.
364 ** gdb.Objfile objects have a new method "add_separate_debug_file".
365 ** A new event "gdb.clear_objfiles" has been added, triggered when
366 selecting a new file to debug.
367 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
368 ** New function gdb.lookup_objfile.
370 New events which are triggered when GDB modifies the state of the
373 ** gdb.events.inferior_call_pre: Function call is about to be made.
374 ** gdb.events.inferior_call_post: Function call has just been made.
375 ** gdb.events.memory_changed: A memory location has been altered.
376 ** gdb.events.register_changed: A register has been altered.
378 * New Python-based convenience functions:
380 ** $_caller_is(name [, number_of_frames])
381 ** $_caller_matches(regexp [, number_of_frames])
382 ** $_any_caller_is(name [, number_of_frames])
383 ** $_any_caller_matches(regexp [, number_of_frames])
385 * GDB now supports the compilation and injection of source code into
386 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
387 to compile the source code to object code, and if successful, inject
388 and execute that code within the current context of the inferior.
389 Currently the C language is supported. The commands used to
390 interface with this new feature are:
392 compile code [-raw|-r] [--] [source code]
393 compile file [-raw|-r] filename
397 demangle [-l language] [--] name
398 Demangle "name" in the specified language, or the current language
399 if elided. This command is renamed from the "maint demangle" command.
400 The latter is kept as a no-op to avoid "maint demangle" being interpreted
401 as "maint demangler-warning".
403 queue-signal signal-name-or-number
404 Queue a signal to be delivered to the thread when it is resumed.
406 add-auto-load-scripts-directory directory
407 Add entries to the list of directories from which to load auto-loaded
410 maint print user-registers
411 List all currently available "user" registers.
413 compile code [-r|-raw] [--] [source code]
414 Compile, inject, and execute in the inferior the executable object
415 code produced by compiling the provided source code.
417 compile file [-r|-raw] filename
418 Compile and inject into the inferior the executable object code
419 produced by compiling the source code stored in the filename
422 * On resume, GDB now always passes the signal the program had stopped
423 for to the thread the signal was sent to, even if the user changed
424 threads before resuming. Previously GDB would often (but not
425 always) deliver the signal to the thread that happens to be current
428 * Conversely, the "signal" command now consistently delivers the
429 requested signal to the current thread. GDB now asks for
430 confirmation if the program had stopped for a signal and the user
431 switched threads meanwhile.
433 * "breakpoint always-inserted" modes "off" and "auto" merged.
435 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
436 won't remove breakpoints from the target until all threads stop,
437 even in non-stop mode. The "auto" mode has been removed, and "off"
438 is now the default mode.
442 set debug symbol-lookup
443 show debug symbol-lookup
444 Control display of debugging info regarding symbol lookup.
448 ** The -list-thread-groups command outputs an exit-code field for
449 inferiors that have exited.
453 MIPS SDE mips*-sde*-elf*
457 Support for these obsolete configurations has been removed.
459 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
460 SGI Irix-5.x mips-*-irix5*
461 SGI Irix-6.x mips-*-irix6*
462 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
463 VAX running Ultrix vax-*-ultrix*
465 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
466 and "assf"), have been removed. Use the "sharedlibrary" command, or
467 its alias "share", instead.
469 *** Changes in GDB 7.8
471 * New command line options
474 This is an alias for the --data-directory option.
476 * GDB supports printing and modifying of variable length automatic arrays
477 as specified in ISO C99.
479 * The ARM simulator now supports instruction level tracing
480 with or without disassembly.
484 GDB now has support for scripting using Guile. Whether this is
485 available is determined at configure time.
486 Guile version 2.0 or greater is required.
487 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
489 * New commands (for set/show, see "New options" below)
493 Invoke CODE by passing it to the Guile interpreter.
497 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
499 info auto-load guile-scripts [regexp]
500 Print the list of automatically loaded Guile scripts.
502 * The source command is now capable of sourcing Guile scripts.
503 This feature is dependent on the debugger being built with Guile support.
507 set print symbol-loading (off|brief|full)
508 show print symbol-loading
509 Control whether to print informational messages when loading symbol
510 information for a file. The default is "full", but when debugging
511 programs with large numbers of shared libraries the amount of output
514 set guile print-stack (none|message|full)
515 show guile print-stack
516 Show a stack trace when an error is encountered in a Guile script.
518 set auto-load guile-scripts (on|off)
519 show auto-load guile-scripts
520 Control auto-loading of Guile script files.
522 maint ada set ignore-descriptive-types (on|off)
523 maint ada show ignore-descriptive-types
524 Control whether the debugger should ignore descriptive types in Ada
525 programs. The default is not to ignore the descriptive types. See
526 the user manual for more details on descriptive types and the intended
527 usage of this option.
529 set auto-connect-native-target
531 Control whether GDB is allowed to automatically connect to the
532 native target for the run, attach, etc. commands when not connected
533 to any target yet. See also "target native" below.
535 set record btrace replay-memory-access (read-only|read-write)
536 show record btrace replay-memory-access
537 Control what memory accesses are allowed during replay.
539 maint set target-async (on|off)
540 maint show target-async
541 This controls whether GDB targets operate in synchronous or
542 asynchronous mode. Normally the default is asynchronous, if it is
543 available; but this can be changed to more easily debug problems
544 occurring only in synchronous mode.
546 set mi-async (on|off)
548 Control whether MI asynchronous mode is preferred. This supersedes
549 "set target-async" of previous GDB versions.
551 * "set target-async" is deprecated as a CLI option and is now an alias
552 for "set mi-async" (only puts MI into async mode).
554 * Background execution commands (e.g., "c&", "s&", etc.) are now
555 possible ``out of the box'' if the target supports them. Previously
556 the user would need to explicitly enable the possibility with the
557 "set target-async on" command.
559 * New features in the GDB remote stub, GDBserver
561 ** New option --debug-format=option1[,option2,...] allows one to add
562 additional text to each output. At present only timestamps
563 are supported: --debug-format=timestamps.
564 Timestamps can also be turned on with the
565 "monitor set debug-format timestamps" command from GDB.
567 * The 'record instruction-history' command now starts counting instructions
568 at one. This also affects the instruction ranges reported by the
569 'record function-call-history' command when given the /i modifier.
571 * The command 'record function-call-history' supports a new modifier '/c' to
572 indent the function names based on their call stack depth.
573 The fields for the '/i' and '/l' modifier have been reordered.
574 The source line range is now prefixed with 'at'.
575 The instruction range is now prefixed with 'inst'.
576 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
577 "record instruction-history" and "list" commands.
579 * The ranges given as arguments to the 'record function-call-history' and
580 'record instruction-history' commands are now inclusive.
582 * The btrace record target now supports the 'record goto' command.
583 For locations inside the execution trace, the back trace is computed
584 based on the information stored in the execution trace.
586 * The btrace record target supports limited reverse execution and replay.
587 The target does not record data and therefore does not allow reading
590 * The "catch syscall" command now works on s390*-linux* targets.
592 * The "compare-sections" command is no longer specific to target
593 remote. It now works with all targets.
595 * All native targets are now consistently called "native".
596 Consequently, the "target child", "target GNU", "target djgpp",
597 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
598 commands have been replaced with "target native". The QNX/NTO port
599 leaves the "procfs" target in place and adds a "native" target for
600 consistency with other ports. The impact on users should be minimal
601 as these commands previously either throwed an error, or were
602 no-ops. The target's name is visible in the output of the following
603 commands: "help target", "info target", "info files", "maint print
606 * The "target native" command now connects to the native target. This
607 can be used to launch native programs even when "set
608 auto-connect-native-target" is set to off.
610 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
612 * Support for Intel(R) AVX-512 registers on GNU/Linux.
613 Support displaying and modifying Intel(R) AVX-512 registers
614 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
618 qXfer:btrace:read's annex
619 The qXfer:btrace:read packet supports a new annex 'delta' to read
620 branch trace incrementally.
624 ** Valid Python operations on gdb.Value objects representing
625 structs/classes invoke the corresponding overloaded operators if
627 ** New `Xmethods' feature in the Python API. Xmethods are
628 additional methods or replacements for existing methods of a C++
629 class. This feature is useful for those cases where a method
630 defined in C++ source code could be inlined or optimized out by
631 the compiler, making it unavailable to GDB.
634 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
636 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
637 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
638 its alias "share", instead.
640 * The commands "set remotebaud" and "show remotebaud" are no longer
641 supported. Use "set serial baud" and "show serial baud" (respectively)
646 ** A new option "-gdb-set mi-async" replaces "-gdb-set
647 target-async". The latter is left as a deprecated alias of the
648 former for backward compatibility. If the target supports it,
649 CLI background execution commands are now always possible by
650 default, independently of whether the frontend stated a
651 preference for asynchronous execution with "-gdb-set mi-async".
652 Previously "-gdb-set target-async off" affected both MI execution
653 commands and CLI execution commands.
655 *** Changes in GDB 7.7
657 * Improved support for process record-replay and reverse debugging on
658 arm*-linux* targets. Support for thumb32 and syscall instruction
659 recording has been added.
661 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
663 * GDB now supports Fission DWP file format version 2.
664 http://gcc.gnu.org/wiki/DebugFission
666 * New convenience function "$_isvoid", to check whether an expression
667 is void. A void expression is an expression where the type of the
668 result is "void". For example, some convenience variables may be
669 "void" when evaluated (e.g., "$_exitcode" before the execution of
670 the program being debugged; or an undefined convenience variable).
671 Another example, when calling a function whose return type is
674 * The "maintenance print objfiles" command now takes an optional regexp.
676 * The "catch syscall" command now works on arm*-linux* targets.
678 * GDB now consistently shows "<not saved>" when printing values of
679 registers the debug info indicates have not been saved in the frame
680 and there's nowhere to retrieve them from
681 (callee-saved/call-clobbered registers):
686 (gdb) info registers rax
689 Before, the former would print "<optimized out>", and the latter
690 "*value not available*".
692 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
697 ** Frame filters and frame decorators have been added.
698 ** Temporary breakpoints are now supported.
699 ** Line tables representation has been added.
700 ** New attribute 'parent_type' for gdb.Field objects.
701 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
702 ** New attribute 'name' for gdb.Type objects.
706 Nios II ELF nios2*-*-elf
707 Nios II GNU/Linux nios2*-*-linux
708 Texas Instruments MSP430 msp430*-*-elf
710 * Removed native configurations
712 Support for these a.out NetBSD and OpenBSD obsolete configurations has
713 been removed. ELF variants of these configurations are kept supported.
715 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
716 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
717 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
718 i[34567]86-*-openbsd3.[0-3]
719 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
720 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
721 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
725 Like "catch throw", but catches a re-thrown exception.
727 Renamed from old "maint check-symtabs".
729 Perform consistency checks on symtabs.
731 Expand symtabs matching an optional regexp.
734 Display the details of GDB configure-time options.
736 maint set|show per-command
737 maint set|show per-command space
738 maint set|show per-command time
739 maint set|show per-command symtab
740 Enable display of per-command gdb resource usage.
742 remove-symbol-file FILENAME
743 remove-symbol-file -a ADDRESS
744 Remove a symbol file added via add-symbol-file. The file to remove
745 can be identified by its filename or by an address that lies within
746 the boundaries of this symbol file in memory.
749 info exceptions REGEXP
750 Display the list of Ada exceptions defined in the program being
751 debugged. If provided, only the exceptions whose names match REGEXP
756 set debug symfile off|on
758 Control display of debugging info regarding reading symbol files and
759 symbol tables within those files
761 set print raw frame-arguments
762 show print raw frame-arguments
763 Set/show whether to print frame arguments in raw mode,
764 disregarding any defined pretty-printers.
766 set remote trace-status-packet
767 show remote trace-status-packet
768 Set/show the use of remote protocol qTStatus packet.
772 Control display of debugging messages related to Nios II targets.
776 Control whether target-assisted range stepping is enabled.
778 set startup-with-shell
779 show startup-with-shell
780 Specifies whether Unix child processes are started via a shell or
785 Use the target memory cache for accesses to the code segment. This
786 improves performance of remote debugging (particularly disassembly).
788 * You can now use a literal value 'unlimited' for options that
789 interpret 0 or -1 as meaning "unlimited". E.g., "set
790 trace-buffer-size unlimited" is now an alias for "set
791 trace-buffer-size -1" and "set height unlimited" is now an alias for
794 * The "set debug symtab-create" debugging option of GDB has been changed to
795 accept a verbosity level. 0 means "off", 1 provides basic debugging
796 output, and values of 2 or greater provides more verbose output.
798 * New command-line options
800 Display the details of GDB configure-time options.
802 * The command 'tsave' can now support new option '-ctf' to save trace
803 buffer in Common Trace Format.
805 * Newly installed $prefix/bin/gcore acts as a shell interface for the
808 * GDB now implements the the C++ 'typeid' operator.
810 * The new convenience variable $_exception holds the exception being
811 thrown or caught at an exception-related catchpoint.
813 * The exception-related catchpoints, like "catch throw", now accept a
814 regular expression which can be used to filter exceptions by type.
816 * The new convenience variable $_exitsignal is automatically set to
817 the terminating signal number when the program being debugged dies
818 due to an uncaught signal.
822 ** All MI commands now accept an optional "--language" option.
823 Support for this feature can be verified by using the "-list-features"
824 command, which should contain "language-option".
826 ** The new command -info-gdb-mi-command allows the user to determine
827 whether a GDB/MI command is supported or not.
829 ** The "^error" result record returned when trying to execute an undefined
830 GDB/MI command now provides a variable named "code" whose content is the
831 "undefined-command" error code. Support for this feature can be verified
832 by using the "-list-features" command, which should contain
833 "undefined-command-error-code".
835 ** The -trace-save MI command can optionally save trace buffer in Common
838 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
840 ** The command -data-list-register-values now accepts an optional
841 "--skip-unavailable" option. When used, only the available registers
844 ** The new command -trace-frame-collected dumps collected variables,
845 computed expressions, tvars, memory and registers in a traceframe.
847 ** The commands -stack-list-locals, -stack-list-arguments and
848 -stack-list-variables now accept an option "--skip-unavailable".
849 When used, only the available locals or arguments are displayed.
851 ** The -exec-run command now accepts an optional "--start" option.
852 When used, the command follows the same semantics as the "start"
853 command, stopping the program's execution at the start of its
854 main subprogram. Support for this feature can be verified using
855 the "-list-features" command, which should contain
856 "exec-run-start-option".
858 ** The new commands -catch-assert and -catch-exceptions insert
859 catchpoints stopping the program when Ada exceptions are raised.
861 ** The new command -info-ada-exceptions provides the equivalent of
862 the new "info exceptions" command.
864 * New system-wide configuration scripts
865 A GDB installation now provides scripts suitable for use as system-wide
866 configuration scripts for the following systems:
870 * GDB now supports target-assigned range stepping with remote targets.
871 This improves the performance of stepping source lines by reducing
872 the number of control packets from/to GDB. See "New remote packets"
875 * GDB now understands the element 'tvar' in the XML traceframe info.
876 It has the id of the collected trace state variables.
878 * On S/390 targets that provide the transactional-execution feature,
879 the program interruption transaction diagnostic block (TDB) is now
880 represented as a number of additional "registers" in GDB.
886 The vCont packet supports a new 'r' action, that tells the remote
887 stub to step through an address range itself, without GDB
888 involvemement at each single-step.
890 qXfer:libraries-svr4:read's annex
891 The previously unused annex of the qXfer:libraries-svr4:read packet
892 is now used to support passing an argument list. The remote stub
893 reports support for this argument list to GDB's qSupported query.
894 The defined arguments are "start" and "prev", used to reduce work
895 necessary for library list updating, resulting in significant
898 * New features in the GDB remote stub, GDBserver
900 ** GDBserver now supports target-assisted range stepping. Currently
901 enabled on x86/x86_64 GNU/Linux targets.
903 ** GDBserver now adds element 'tvar' in the XML in the reply to
904 'qXfer:traceframe-info:read'. It has the id of the collected
905 trace state variables.
907 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
910 * New 'z' formatter for printing and examining memory, this displays the
911 value as hexadecimal zero padded on the left to the size of the type.
913 * GDB can now use Windows x64 unwinding data.
915 * The "set remotebaud" command has been replaced by "set serial baud".
916 Similarly, "show remotebaud" has been replaced by "show serial baud".
917 The "set remotebaud" and "show remotebaud" commands are still available
918 to provide backward compatibility with older versions of GDB.
920 *** Changes in GDB 7.6
922 * Target record has been renamed to record-full.
923 Record/replay is now enabled with the "record full" command.
924 This also affects settings that are associated with full record/replay
925 that have been moved from "set/show record" to "set/show record full":
927 set|show record full insn-number-max
928 set|show record full stop-at-limit
929 set|show record full memory-query
931 * A new record target "record-btrace" has been added. The new target
932 uses hardware support to record the control-flow of a process. It
933 does not support replaying the execution, but it implements the
934 below new commands for investigating the recorded execution log.
935 This new recording method can be enabled using:
939 The "record-btrace" target is only available on Intel Atom processors
940 and requires a Linux kernel 2.6.32 or later.
942 * Two new commands have been added for record/replay to give information
943 about the recorded execution without having to replay the execution.
944 The commands are only supported by "record btrace".
946 record instruction-history prints the execution history at
947 instruction granularity
949 record function-call-history prints the execution history at
952 * New native configurations
954 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
955 FreeBSD/powerpc powerpc*-*-freebsd
956 x86_64/Cygwin x86_64-*-cygwin*
957 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
961 ARM AArch64 aarch64*-*-elf
962 ARM AArch64 GNU/Linux aarch64*-*-linux
963 Lynx 178 PowerPC powerpc-*-lynx*178
964 x86_64/Cygwin x86_64-*-cygwin*
965 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
967 * If the configured location of system.gdbinit file (as given by the
968 --with-system-gdbinit option at configure time) is in the
969 data-directory (as specified by --with-gdb-datadir at configure
970 time) or in one of its subdirectories, then GDB will look for the
971 system-wide init file in the directory specified by the
972 --data-directory command-line option.
974 * New command line options:
976 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
977 other initialization files, unlike -nx which disables all of them.
979 * Removed command line options
981 -epoch This was used by the gdb mode in Epoch, an ancient fork of
984 * The 'ptype' and 'whatis' commands now accept an argument to control
987 * 'info proc' now works on some core files.
991 ** Vectors can be created with gdb.Type.vector.
993 ** Python's atexit.register now works in GDB.
995 ** Types can be pretty-printed via a Python API.
997 ** Python 3 is now supported (in addition to Python 2.4 or later)
999 ** New class gdb.Architecture exposes GDB's internal representation
1000 of architecture in the Python API.
1002 ** New method Frame.architecture returns the gdb.Architecture object
1003 corresponding to the frame's architecture.
1005 * New Python-based convenience functions:
1007 ** $_memeq(buf1, buf2, length)
1008 ** $_streq(str1, str2)
1010 ** $_regex(str, regex)
1012 * The 'cd' command now defaults to using '~' (the home directory) if not
1015 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1016 default for GCC since November 2000.
1018 * The command 'forward-search' can now be abbreviated as 'fo'.
1020 * The command 'info tracepoints' can now display 'installed on target'
1021 or 'not installed on target' for each non-pending location of tracepoint.
1023 * New configure options
1025 --enable-libmcheck/--disable-libmcheck
1026 By default, development versions are built with -lmcheck on hosts
1027 that support it, in order to help track memory corruption issues.
1028 Release versions, on the other hand, are built without -lmcheck
1029 by default. The --enable-libmcheck/--disable-libmcheck configure
1030 options allow the user to override that default.
1031 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1032 This configure option allows the user to build GDB with
1033 libbabeltrace using which GDB can read Common Trace Format data.
1035 * New commands (for set/show, see "New options" below)
1038 Catch signals. This is similar to "handle", but allows commands and
1039 conditions to be attached.
1042 List the BFDs known to GDB.
1044 python-interactive [command]
1046 Start a Python interactive prompt, or evaluate the optional command
1047 and print the result of expressions.
1050 "py" is a new alias for "python".
1052 enable type-printer [name]...
1053 disable type-printer [name]...
1054 Enable or disable type printers.
1058 ** For the Renesas Super-H architecture, the "regs" command has been removed
1059 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1064 set print type methods (on|off)
1065 show print type methods
1066 Control whether method declarations are displayed by "ptype".
1067 The default is to show them.
1069 set print type typedefs (on|off)
1070 show print type typedefs
1071 Control whether typedef definitions are displayed by "ptype".
1072 The default is to show them.
1074 set filename-display basename|relative|absolute
1075 show filename-display
1076 Control the way in which filenames is displayed.
1077 The default is "relative", which preserves previous behavior.
1079 set trace-buffer-size
1080 show trace-buffer-size
1081 Request target to change the size of trace buffer.
1083 set remote trace-buffer-size-packet auto|on|off
1084 show remote trace-buffer-size-packet
1085 Control the use of the remote protocol `QTBuffer:size' packet.
1089 Control display of debugging messages related to ARM AArch64.
1092 set debug coff-pe-read
1093 show debug coff-pe-read
1094 Control display of debugging messages related to reading of COFF/PE
1099 Control display of debugging messages related to Mach-O symbols
1102 set debug notification
1103 show debug notification
1104 Control display of debugging info for async remote notification.
1108 ** Command parameter changes are now notified using new async record
1109 "=cmd-param-changed".
1110 ** Trace frame changes caused by command "tfind" are now notified using
1111 new async record "=traceframe-changed".
1112 ** The creation, deletion and modification of trace state variables
1113 are now notified using new async records "=tsv-created",
1114 "=tsv-deleted" and "=tsv-modified".
1115 ** The start and stop of process record are now notified using new
1116 async record "=record-started" and "=record-stopped".
1117 ** Memory changes are now notified using new async record
1119 ** The data-disassemble command response will include a "fullname" field
1120 containing the absolute file name when source has been requested.
1121 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1122 command, to allow pattern filling of memory areas.
1123 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1124 library load/unload events.
1125 ** The response to breakpoint commands and breakpoint async records
1126 includes an "installed" field containing a boolean state about each
1127 non-pending tracepoint location is whether installed on target or not.
1128 ** Output of the "-trace-status" command includes a "trace-file" field
1129 containing the name of the trace file being examined. This field is
1130 optional, and only present when examining a trace file.
1131 ** The "fullname" field is now always present along with the "file" field,
1132 even if the file cannot be found by GDB.
1134 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1135 You must have the LZMA library available when configuring GDB for this
1136 feature to be enabled. For more information, see:
1137 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1139 * New remote packets
1142 Set the size of trace buffer. The remote stub reports support for this
1143 packet to gdb's qSupported query.
1146 Enable Branch Trace Store (BTS)-based branch tracing for the current
1147 thread. The remote stub reports support for this packet to gdb's
1151 Disable branch tracing for the current thread. The remote stub reports
1152 support for this packet to gdb's qSupported query.
1155 Read the traced branches for the current thread. The remote stub
1156 reports support for this packet to gdb's qSupported query.
1158 *** Changes in GDB 7.5
1160 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1161 for more x32 ABI info.
1163 * GDB now supports access to MIPS DSP registers on Linux targets.
1165 * GDB now supports debugging microMIPS binaries.
1167 * The "info os" command on GNU/Linux can now display information on
1168 several new classes of objects managed by the operating system:
1169 "info os procgroups" lists process groups
1170 "info os files" lists file descriptors
1171 "info os sockets" lists internet-domain sockets
1172 "info os shm" lists shared-memory regions
1173 "info os semaphores" lists semaphores
1174 "info os msg" lists message queues
1175 "info os modules" lists loaded kernel modules
1177 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1178 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1179 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1180 options and inspect the probe arguments using the new $_probe_arg family
1181 of convenience variables. You can obtain more information about SystemTap
1182 in <http://sourceware.org/systemtap/>.
1184 * GDB now supports reversible debugging on ARM, it allows you to
1185 debug basic ARM and THUMB instructions, and provides
1186 record/replay support.
1188 * The option "symbol-reloading" has been deleted as it is no longer used.
1192 ** GDB commands implemented in Python can now be put in command class
1195 ** The "maint set python print-stack on|off" is now deleted.
1197 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1198 apply "flag enum"-style pretty-printing to any enum.
1200 ** gdb.lookup_symbol can now work when there is no current frame.
1202 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1203 the source at which the symbol was defined.
1205 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1206 method 'value'. The former indicates whether the symbol needs a
1207 frame in order to compute its value, and the latter computes the
1210 ** A new method 'referenced_value' on gdb.Value objects which can
1211 dereference pointer as well as C++ reference values.
1213 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1214 which return the global and static blocks (as gdb.Block objects),
1215 of the underlying symbol table, respectively.
1217 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1218 object associated with a PC value.
1220 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1221 of the address range occupied by code for the current source line.
1223 * Go language support.
1224 GDB now supports debugging programs written in the Go programming
1227 * GDBserver now supports stdio connections.
1228 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1230 * The binary "gdbtui" can no longer be built or installed.
1231 Use "gdb -tui" instead.
1233 * GDB will now print "flag" enums specially. A flag enum is one where
1234 all the enumerator values have no bits in common when pairwise
1235 "and"ed. When printing a value whose type is a flag enum, GDB will
1236 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1237 (gdb) print (enum E) 3
1240 * The filename part of a linespec will now match trailing components
1241 of a source file name. For example, "break gcc/expr.c:1000" will
1242 now set a breakpoint in build/gcc/expr.c, but not
1243 build/libcpp/expr.c.
1245 * The "info proc" and "generate-core-file" commands will now also
1246 work on remote targets connected to GDBserver on Linux.
1248 * The command "info catch" has been removed. It has been disabled
1249 since December 2007.
1251 * The "catch exception" and "catch assert" commands now accept
1252 a condition at the end of the command, much like the "break"
1253 command does. For instance:
1255 (gdb) catch exception Constraint_Error if Barrier = True
1257 Previously, it was possible to add a condition to such catchpoints,
1258 but it had to be done as a second step, after the catchpoint had been
1259 created, using the "condition" command.
1261 * The "info static-tracepoint-marker" command will now also work on
1262 native Linux targets with in-process agent.
1264 * GDB can now set breakpoints on inlined functions.
1266 * The .gdb_index section has been updated to include symbols for
1267 inlined functions. GDB will ignore older .gdb_index sections by
1268 default, which could cause symbol files to be loaded more slowly
1269 until their .gdb_index sections can be recreated. The new command
1270 "set use-deprecated-index-sections on" will cause GDB to use any older
1271 .gdb_index sections it finds. This will restore performance, but the
1272 ability to set breakpoints on inlined functions will be lost in symbol
1273 files with older .gdb_index sections.
1275 The .gdb_index section has also been updated to record more information
1276 about each symbol. This speeds up the "info variables", "info functions"
1277 and "info types" commands when used with programs having the .gdb_index
1278 section, as well as speeding up debugging with shared libraries using
1279 the .gdb_index section.
1281 * Ada support for GDB/MI Variable Objects has been added.
1283 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1288 ** New command -info-os is the MI equivalent of "info os".
1290 ** Output logs ("set logging" and related) now include MI output.
1294 ** "set use-deprecated-index-sections on|off"
1295 "show use-deprecated-index-sections on|off"
1296 Controls the use of deprecated .gdb_index sections.
1298 ** "catch load" and "catch unload" can be used to stop when a shared
1299 library is loaded or unloaded, respectively.
1301 ** "enable count" can be used to auto-disable a breakpoint after
1304 ** "info vtbl" can be used to show the virtual method tables for
1305 C++ and Java objects.
1307 ** "explore" and its sub commands "explore value" and "explore type"
1308 can be used to recursively explore values and types of
1309 expressions. These commands are available only if GDB is
1310 configured with '--with-python'.
1312 ** "info auto-load" shows status of all kinds of auto-loaded files,
1313 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1314 sequences of commands files, "info auto-load python-scripts"
1315 shows status of auto-loading Python script files,
1316 "info auto-load local-gdbinit" shows status of loading init file
1317 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1318 status of inferior specific thread debugging shared library loading.
1320 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1321 and "show auto-load-scripts" commands have been deprecated, use their
1322 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1323 and "show auto-load python-scripts" counterparts instead.
1325 ** "dprintf location,format,args..." creates a dynamic printf, which
1326 is basically a breakpoint that does a printf and immediately
1327 resumes your program's execution, so it is like a printf that you
1328 can insert dynamically at runtime instead of at compiletime.
1330 ** "set print symbol"
1332 Controls whether GDB attempts to display the symbol, if any,
1333 corresponding to addresses it prints. This defaults to "on", but
1334 you can set it to "off" to restore GDB's previous behavior.
1336 * Deprecated commands
1338 ** For the Renesas Super-H architecture, the "regs" command has been
1339 deprecated, and "info all-registers" should be used instead.
1343 Renesas RL78 rl78-*-elf
1344 HP OpenVMS ia64 ia64-hp-openvms*
1346 * GDBserver supports evaluation of breakpoint conditions. When
1347 support is advertised by GDBserver, GDB may be told to send the
1348 breakpoint conditions in bytecode form to GDBserver. GDBserver
1349 will only report the breakpoint trigger to GDB when its condition
1354 set mips compression
1355 show mips compression
1356 Select the compressed ISA encoding used in functions that have no symbol
1357 information available. The encoding can be set to either of:
1360 and is updated automatically from ELF file flags if available.
1362 set breakpoint condition-evaluation
1363 show breakpoint condition-evaluation
1364 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1365 GDBserver ("target"). Default option "auto" chooses the most efficient
1367 This option can improve debugger efficiency depending on the speed of the
1371 Disable auto-loading globally.
1374 Show auto-loading setting of all kinds of auto-loaded files.
1376 set auto-load gdb-scripts on|off
1377 show auto-load gdb-scripts
1378 Control auto-loading of GDB canned sequences of commands files.
1380 set auto-load python-scripts on|off
1381 show auto-load python-scripts
1382 Control auto-loading of Python script files.
1384 set auto-load local-gdbinit on|off
1385 show auto-load local-gdbinit
1386 Control loading of init file (.gdbinit) from current directory.
1388 set auto-load libthread-db on|off
1389 show auto-load libthread-db
1390 Control auto-loading of inferior specific thread debugging shared library.
1392 set auto-load scripts-directory <dir1>[:<dir2>...]
1393 show auto-load scripts-directory
1394 Set a list of directories from which to load auto-loaded scripts.
1395 Automatically loaded Python scripts and GDB scripts are located in one
1396 of the directories listed by this option.
1397 The delimiter (':' above) may differ according to the host platform.
1399 set auto-load safe-path <dir1>[:<dir2>...]
1400 show auto-load safe-path
1401 Set a list of directories from which it is safe to auto-load files.
1402 The delimiter (':' above) may differ according to the host platform.
1404 set debug auto-load on|off
1405 show debug auto-load
1406 Control display of debugging info for auto-loading the files above.
1408 set dprintf-style gdb|call|agent
1410 Control the way in which a dynamic printf is performed; "gdb"
1411 requests a GDB printf command, while "call" causes dprintf to call a
1412 function in the inferior. "agent" requests that the target agent
1413 (such as GDBserver) do the printing.
1415 set dprintf-function <expr>
1416 show dprintf-function
1417 set dprintf-channel <expr>
1418 show dprintf-channel
1419 Set the function and optional first argument to the call when using
1420 the "call" style of dynamic printf.
1422 set disconnected-dprintf on|off
1423 show disconnected-dprintf
1424 Control whether agent-style dynamic printfs continue to be in effect
1425 after GDB disconnects.
1427 * New configure options
1429 --with-auto-load-dir
1430 Configure default value for the 'set auto-load scripts-directory'
1431 setting above. It defaults to '$debugdir:$datadir/auto-load',
1432 $debugdir representing global debugging info directories (available
1433 via 'show debug-file-directory') and $datadir representing GDB's data
1434 directory (available via 'show data-directory').
1436 --with-auto-load-safe-path
1437 Configure default value for the 'set auto-load safe-path' setting
1438 above. It defaults to the --with-auto-load-dir setting.
1440 --without-auto-load-safe-path
1441 Set 'set auto-load safe-path' to '/', effectively disabling this
1444 * New remote packets
1446 z0/z1 conditional breakpoints extension
1448 The z0/z1 breakpoint insertion packets have been extended to carry
1449 a list of conditional expressions over to the remote stub depending on the
1450 condition evaluation mode. The use of this extension can be controlled
1451 via the "set remote conditional-breakpoints-packet" command.
1455 Specify the signals which the remote stub may pass to the debugged
1456 program without GDB involvement.
1458 * New command line options
1460 --init-command=FILE, -ix Like --command, -x but execute it
1461 before loading inferior.
1462 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1463 execute it before loading inferior.
1465 *** Changes in GDB 7.4
1467 * GDB now handles ambiguous linespecs more consistently; the existing
1468 FILE:LINE support has been expanded to other types of linespecs. A
1469 breakpoint will now be set on all matching locations in all
1470 inferiors, and locations will be added or removed according to
1473 * GDB now allows you to skip uninteresting functions and files when
1474 stepping with the "skip function" and "skip file" commands.
1476 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1477 and "show remote hardware-watchpoint-length-limit". These allows to
1478 set or show the maximum length limit (in bytes) of a remote
1479 target hardware watchpoint.
1481 This allows e.g. to use "unlimited" hardware watchpoints with the
1482 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1483 watchpoints are slower than real hardware watchpoints but are
1484 significantly faster than gdb software watchpoints.
1488 ** The register_pretty_printer function in module gdb.printing now takes
1489 an optional `replace' argument. If True, the new printer replaces any
1492 ** The "maint set python print-stack on|off" command has been
1493 deprecated and will be deleted in GDB 7.5.
1494 A new command: "set python print-stack none|full|message" has
1495 replaced it. Additionally, the default for "print-stack" is
1496 now "message", which just prints the error message without
1499 ** A prompt substitution hook (prompt_hook) is now available to the
1502 ** A new Python module, gdb.prompt has been added to the GDB Python
1503 modules library. This module provides functionality for
1504 escape sequences in prompts (used by set/show
1505 extended-prompt). These escape sequences are replaced by their
1506 corresponding value.
1508 ** Python commands and convenience-functions located in
1509 'data-directory'/python/gdb/command and
1510 'data-directory'/python/gdb/function are now automatically loaded
1513 ** Blocks now provide four new attributes. global_block and
1514 static_block will return the global and static blocks
1515 respectively. is_static and is_global are boolean attributes
1516 that indicate if the block is one of those two types.
1518 ** Symbols now provide the "type" attribute, the type of the symbol.
1520 ** The "gdb.breakpoint" function has been deprecated in favor of
1523 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1524 of a function. This class is based on the "finish" command
1525 available in the CLI.
1527 ** Type objects for struct and union types now allow access to
1528 the fields using standard Python dictionary (mapping) methods.
1529 For example, "some_type['myfield']" now works, as does
1530 "some_type.items()".
1532 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1535 ** A new function, "deep_items" has been added to the gdb.types
1536 module in the GDB Python modules library. This function returns
1537 an iterator over the fields of a struct or union type. Unlike
1538 the standard Python "iteritems" method, it will recursively traverse
1539 any anonymous fields.
1543 ** "*stopped" events can report several new "reason"s, such as
1546 ** Breakpoint changes are now notified using new async records, like
1547 "=breakpoint-modified".
1549 ** New command -ada-task-info.
1551 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1552 $sdir specifies the default system locations of shared libraries.
1553 $pdir specifies the directory where the libpthread used by the application
1556 GDB no longer looks in $sdir and $pdir after it has searched the directories
1557 mentioned in libthread-db-search-path. If you want to search those
1558 directories, they must be specified in libthread-db-search-path.
1559 The default value of libthread-db-search-path on GNU/Linux and Solaris
1560 systems is now "$sdir:$pdir".
1562 $pdir is not supported by gdbserver, it is currently ignored.
1563 $sdir is supported by gdbserver.
1565 * New configure option --with-iconv-bin.
1566 When using the internationalization support like the one in the GNU C
1567 library, GDB will invoke the "iconv" program to get a list of supported
1568 character sets. If this program lives in a non-standard location, one can
1569 use this option to specify where to find it.
1571 * When natively debugging programs on PowerPC BookE processors running
1572 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1573 watchpoints, which specify a mask in addition to an address to watch.
1574 The mask specifies that some bits of an address (the bits which are
1575 reset in the mask) should be ignored when matching the address accessed
1576 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1577 section in the user manual for more details.
1579 * The new option --once causes GDBserver to stop listening for connections once
1580 the first connection is made. The listening port used by GDBserver will
1581 become available after that.
1583 * New commands "info macros" and "alias" have been added.
1585 * New function parameters suffix @entry specifies value of function parameter
1586 at the time the function got called. Entry values are available only since
1592 "!" is now an alias of the "shell" command.
1593 Note that no space is needed between "!" and SHELL COMMAND.
1597 watch EXPRESSION mask MASK_VALUE
1598 The watch command now supports the mask argument which allows creation
1599 of masked watchpoints, if the current architecture supports this feature.
1601 info auto-load-scripts [REGEXP]
1602 This command was formerly named "maintenance print section-scripts".
1603 It is now generally useful and is no longer a maintenance-only command.
1605 info macro [-all] [--] MACRO
1606 The info macro command has new options `-all' and `--'. The first for
1607 printing all definitions of a macro. The second for explicitly specifying
1608 the end of arguments and the beginning of the macro name in case the macro
1609 name starts with a hyphen.
1611 collect[/s] EXPRESSIONS
1612 The tracepoint collect command now takes an optional modifier "/s"
1613 that directs it to dereference pointer-to-character types and
1614 collect the bytes of memory up to a zero byte. The behavior is
1615 similar to what you see when you use the regular print command on a
1616 string. An optional integer following the "/s" sets a bound on the
1617 number of bytes that will be collected.
1620 The trace start command now interprets any supplied arguments as a
1621 note to be recorded with the trace run, with an effect similar to
1622 setting the variable trace-notes.
1625 The trace stop command now interprets any arguments as a note to be
1626 mentioned along with the tstatus report that the trace was stopped
1627 with a command. The effect is similar to setting the variable
1630 * Tracepoints can now be enabled and disabled at any time after a trace
1631 experiment has been started using the standard "enable" and "disable"
1632 commands. It is now possible to start a trace experiment with no enabled
1633 tracepoints; GDB will display a warning, but will allow the experiment to
1634 begin, assuming that tracepoints will be enabled as needed while the trace
1637 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1638 locations with 4-byte instructions, when they were previously
1639 limited to locations with instructions of 5 bytes or longer.
1643 set debug dwarf2-read
1644 show debug dwarf2-read
1645 Turns on or off display of debugging messages related to reading
1646 DWARF debug info. The default is off.
1648 set debug symtab-create
1649 show debug symtab-create
1650 Turns on or off display of debugging messages related to symbol table
1651 creation. The default is off.
1654 show extended-prompt
1655 Set the GDB prompt, and allow escape sequences to be inserted to
1656 display miscellaneous information (see 'help set extended-prompt'
1657 for the list of sequences). This prompt (and any information
1658 accessed through the escape sequences) is updated every time the
1659 prompt is displayed.
1661 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1662 show print entry-values
1663 Set printing of frame argument values at function entry. In some cases
1664 GDB can determine the value of function argument which was passed by the
1665 function caller, even if the value was modified inside the called function.
1667 set debug entry-values
1668 show debug entry-values
1669 Control display of debugging info for determining frame argument values at
1670 function entry and virtual tail call frames.
1672 set basenames-may-differ
1673 show basenames-may-differ
1674 Set whether a source file may have multiple base names.
1675 (A "base name" is the name of a file with the directory part removed.
1676 Example: The base name of "/home/user/hello.c" is "hello.c".)
1677 If set, GDB will canonicalize file names (e.g., expand symlinks)
1678 before comparing them. Canonicalization is an expensive operation,
1679 but it allows the same file be known by more than one base name.
1680 If not set (the default), all source files are assumed to have just
1681 one base name, and gdb will do file name comparisons more efficiently.
1687 Set a user name and notes for the current and any future trace runs.
1688 This is useful for long-running and/or disconnected traces, to
1689 inform others (or yourself) as to who is running the trace, supply
1690 contact information, or otherwise explain what is going on.
1692 set trace-stop-notes
1693 show trace-stop-notes
1694 Set a note attached to the trace run, that is displayed when the
1695 trace has been stopped by a tstop command. This is useful for
1696 instance as an explanation, if you are stopping a trace run that was
1697 started by someone else.
1699 * New remote packets
1703 Dynamically enable a tracepoint in a started trace experiment.
1707 Dynamically disable a tracepoint in a started trace experiment.
1711 Set the user and notes of the trace run.
1715 Query the current status of a tracepoint.
1719 Query the minimum length of instruction at which a fast tracepoint may
1722 * Dcache size (number of lines) and line-size are now runtime-configurable
1723 via "set dcache line" and "set dcache line-size" commands.
1727 Texas Instruments TMS320C6x tic6x-*-*
1731 Renesas RL78 rl78-*-elf
1733 *** Changes in GDB 7.3.1
1735 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1737 *** Changes in GDB 7.3
1739 * GDB has a new command: "thread find [REGEXP]".
1740 It finds the thread id whose name, target id, or thread extra info
1741 matches the given regular expression.
1743 * The "catch syscall" command now works on mips*-linux* targets.
1745 * The -data-disassemble MI command now supports modes 2 and 3 for
1746 dumping the instruction opcodes.
1748 * New command line options
1750 -data-directory DIR Specify DIR as the "data-directory".
1751 This is mostly for testing purposes.
1753 * The "maint set python auto-load on|off" command has been renamed to
1754 "set auto-load-scripts on|off".
1756 * GDB has a new command: "set directories".
1757 It is like the "dir" command except that it replaces the
1758 source path list instead of augmenting it.
1760 * GDB now understands thread names.
1762 On GNU/Linux, "info threads" will display the thread name as set by
1763 prctl or pthread_setname_np.
1765 There is also a new command, "thread name", which can be used to
1766 assign a name internally for GDB to display.
1769 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1770 has been integrated into GDB.
1774 ** The function gdb.Write now accepts an optional keyword 'stream'.
1775 This keyword, when provided, will direct the output to either
1776 stdout, stderr, or GDB's logging output.
1778 ** Parameters can now be be sub-classed in Python, and in particular
1779 you may implement the get_set_doc and get_show_doc functions.
1780 This improves how Parameter set/show documentation is processed
1781 and allows for more dynamic content.
1783 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1784 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1785 have an is_valid method.
1787 ** Breakpoints can now be sub-classed in Python, and in particular
1788 you may implement a 'stop' function that is executed each time
1789 the inferior reaches that breakpoint.
1791 ** New function gdb.lookup_global_symbol looks up a global symbol.
1793 ** GDB values in Python are now callable if the value represents a
1794 function. For example, if 'some_value' represents a function that
1795 takes two integer parameters and returns a value, you can call
1796 that function like so:
1798 result = some_value (10,20)
1800 ** Module gdb.types has been added.
1801 It contains a collection of utilities for working with gdb.Types objects:
1802 get_basic_type, has_field, make_enum_dict.
1804 ** Module gdb.printing has been added.
1805 It contains utilities for writing and registering pretty-printers.
1806 New classes: PrettyPrinter, SubPrettyPrinter,
1807 RegexpCollectionPrettyPrinter.
1808 New function: register_pretty_printer.
1810 ** New commands "info pretty-printers", "enable pretty-printer" and
1811 "disable pretty-printer" have been added.
1813 ** gdb.parameter("directories") is now available.
1815 ** New function gdb.newest_frame returns the newest frame in the
1818 ** The gdb.InferiorThread class has a new "name" attribute. This
1819 holds the thread's name.
1821 ** Python Support for Inferior events.
1822 Python scripts can add observers to be notified of events
1823 occurring in the process being debugged.
1824 The following events are currently supported:
1825 - gdb.events.cont Continue event.
1826 - gdb.events.exited Inferior exited event.
1827 - gdb.events.stop Signal received, and Breakpoint hit events.
1831 ** GDB now puts template parameters in scope when debugging in an
1832 instantiation. For example, if you have:
1834 template<int X> int func (void) { return X; }
1836 then if you step into func<5>, "print X" will show "5". This
1837 feature requires proper debuginfo support from the compiler; it
1838 was added to GCC 4.5.
1840 ** The motion commands "next", "finish", "until", and "advance" now
1841 work better when exceptions are thrown. In particular, GDB will
1842 no longer lose control of the inferior; instead, the GDB will
1843 stop the inferior at the point at which the exception is caught.
1844 This functionality requires a change in the exception handling
1845 code that was introduced in GCC 4.5.
1847 * GDB now follows GCC's rules on accessing volatile objects when
1848 reading or writing target state during expression evaluation.
1849 One notable difference to prior behavior is that "print x = 0"
1850 no longer generates a read of x; the value of the assignment is
1851 now always taken directly from the value being assigned.
1853 * GDB now has some support for using labels in the program's source in
1854 linespecs. For instance, you can use "advance label" to continue
1855 execution to a label.
1857 * GDB now has support for reading and writing a new .gdb_index
1858 section. This section holds a fast index of DWARF debugging
1859 information and can be used to greatly speed up GDB startup and
1860 operation. See the documentation for `save gdb-index' for details.
1862 * The "watch" command now accepts an optional "-location" argument.
1863 When used, this causes GDB to watch the memory referred to by the
1864 expression. Such a watchpoint is never deleted due to it going out
1867 * GDB now supports thread debugging of core dumps on GNU/Linux.
1869 GDB now activates thread debugging using the libthread_db library
1870 when debugging GNU/Linux core dumps, similarly to when debugging
1871 live processes. As a result, when debugging a core dump file, GDB
1872 is now able to display pthread_t ids of threads. For example, "info
1873 threads" shows the same output as when debugging the process when it
1874 was live. In earlier releases, you'd see something like this:
1877 * 1 LWP 6780 main () at main.c:10
1879 While now you see this:
1882 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1884 It is also now possible to inspect TLS variables when debugging core
1887 When debugging a core dump generated on a machine other than the one
1888 used to run GDB, you may need to point GDB at the correct
1889 libthread_db library with the "set libthread-db-search-path"
1890 command. See the user manual for more details on this command.
1892 * When natively debugging programs on PowerPC BookE processors running
1893 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1894 which stop execution of the inferior whenever it executes an instruction
1895 at any address within the specified range. See the "PowerPC Embedded"
1896 section in the user manual for more details.
1898 * New features in the GDB remote stub, GDBserver
1900 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1901 and i686 LynxOS (version 5.x).
1903 ** GDBserver is now supported on Blackfin Linux.
1905 * New native configurations
1907 ia64 HP-UX ia64-*-hpux*
1911 Analog Devices, Inc. Blackfin Processor bfin-*
1913 * Ada task switching is now supported on sparc-elf targets when
1914 debugging a program using the Ravenscar Profile. For more information,
1915 see the "Tasking Support when using the Ravenscar Profile" section
1916 in the GDB user manual.
1918 * Guile support was removed.
1920 * New features in the GNU simulator
1922 ** The --map-info flag lists all known core mappings.
1924 ** CFI flashes may be simulated via the "cfi" device.
1926 *** Changes in GDB 7.2
1928 * Shared library support for remote targets by default
1930 When GDB is configured for a generic, non-OS specific target, like
1931 for example, --target=arm-eabi or one of the many *-*-elf targets,
1932 GDB now queries remote stubs for loaded shared libraries using the
1933 `qXfer:libraries:read' packet. Previously, shared library support
1934 was always disabled for such configurations.
1938 ** Argument Dependent Lookup (ADL)
1940 In C++ ADL lookup directs function search to the namespaces of its
1941 arguments even if the namespace has not been imported.
1951 Here the compiler will search for `foo' in the namespace of 'b'
1952 and find A::foo. GDB now supports this. This construct is commonly
1953 used in the Standard Template Library for operators.
1955 ** Improved User Defined Operator Support
1957 In addition to member operators, GDB now supports lookup of operators
1958 defined in a namespace and imported with a `using' directive, operators
1959 defined in the global scope, operators imported implicitly from an
1960 anonymous namespace, and the ADL operators mentioned in the previous
1962 GDB now also supports proper overload resolution for all the previously
1963 mentioned flavors of operators.
1965 ** static const class members
1967 Printing of static const class members that are initialized in the
1968 class definition has been fixed.
1970 * Windows Thread Information Block access.
1972 On Windows targets, GDB now supports displaying the Windows Thread
1973 Information Block (TIB) structure. This structure is visible either
1974 by using the new command `info w32 thread-information-block' or, by
1975 dereferencing the new convenience variable named `$_tlb', a
1976 thread-specific pointer to the TIB. This feature is also supported
1977 when remote debugging using GDBserver.
1979 * Static tracepoints
1981 Static tracepoints are calls in the user program into a tracing
1982 library. One such library is a port of the LTTng kernel tracer to
1983 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1984 When debugging with GDBserver, GDB now supports combining the GDB
1985 tracepoint machinery with such libraries. For example: the user can
1986 use GDB to probe a static tracepoint marker (a call from the user
1987 program into the tracing library) with the new "strace" command (see
1988 "New commands" below). This creates a "static tracepoint" in the
1989 breakpoint list, that can be manipulated with the same feature set
1990 as fast and regular tracepoints. E.g., collect registers, local and
1991 global variables, collect trace state variables, and define
1992 tracepoint conditions. In addition, the user can collect extra
1993 static tracepoint marker specific data, by collecting the new
1994 $_sdata internal variable. When analyzing the trace buffer, you can
1995 inspect $_sdata like any other variable available to GDB. For more
1996 information, see the "Tracepoints" chapter in GDB user manual. New
1997 remote packets have been defined to support static tracepoints, see
1998 the "New remote packets" section below.
2000 * Better reconstruction of tracepoints after disconnected tracing
2002 GDB will attempt to download the original source form of tracepoint
2003 definitions when starting a trace run, and then will upload these
2004 upon reconnection to the target, resulting in a more accurate
2005 reconstruction of the tracepoints that are in use on the target.
2009 You can now exercise direct control over the ways that GDB can
2010 affect your program. For instance, you can disallow the setting of
2011 breakpoints, so that the program can run continuously (assuming
2012 non-stop mode). In addition, the "observer" variable is available
2013 to switch all of the different controls; in observer mode, GDB
2014 cannot affect the target's behavior at all, which is useful for
2015 tasks like diagnosing live systems in the field.
2017 * The new convenience variable $_thread holds the number of the
2020 * New remote packets
2024 Return the address of the Windows Thread Information Block of a given thread.
2028 In response to several of the tracepoint packets, the target may now
2029 also respond with a number of intermediate `qRelocInsn' request
2030 packets before the final result packet, to have GDB handle
2031 relocating an instruction to execute at a different address. This
2032 is particularly useful for stubs that support fast tracepoints. GDB
2033 reports support for this feature in the qSupported packet.
2037 List static tracepoint markers in the target program.
2041 List static tracepoint markers at a given address in the target
2044 qXfer:statictrace:read
2046 Read the static trace data collected (by a `collect $_sdata'
2047 tracepoint action). The remote stub reports support for this packet
2048 to gdb's qSupported query.
2052 Send the current settings of GDB's permission flags.
2056 Send part of the source (textual) form of a tracepoint definition,
2057 which includes location, conditional, and action list.
2059 * The source command now accepts a -s option to force searching for the
2060 script in the source search path even if the script name specifies
2063 * New features in the GDB remote stub, GDBserver
2065 - GDBserver now support tracepoints (including fast tracepoints, and
2066 static tracepoints). The feature is currently supported by the
2067 i386-linux and amd64-linux builds. See the "Tracepoints support
2068 in gdbserver" section in the manual for more information.
2070 GDBserver JIT compiles the tracepoint's conditional agent
2071 expression bytecode into native code whenever possible for low
2072 overhead dynamic tracepoints conditionals. For such tracepoints,
2073 an expression that examines program state is evaluated when the
2074 tracepoint is reached, in order to determine whether to capture
2075 trace data. If the condition is simple and false, processing the
2076 tracepoint finishes very quickly and no data is gathered.
2078 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2079 for static tracepoints support.
2081 - GDBserver now supports x86_64 Windows 64-bit debugging.
2083 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2084 it understands register description.
2086 * The --batch flag now disables pagination and queries.
2088 * X86 general purpose registers
2090 GDB now supports reading/writing byte, word and double-word x86
2091 general purpose registers directly. This means you can use, say,
2092 $ah or $ax to refer, respectively, to the byte register AH and
2093 16-bit word register AX that are actually portions of the 32-bit
2094 register EAX or 64-bit register RAX.
2096 * The `commands' command now accepts a range of breakpoints to modify.
2097 A plain `commands' following a command that creates multiple
2098 breakpoints affects all the breakpoints set by that command. This
2099 applies to breakpoints set by `rbreak', and also applies when a
2100 single `break' command creates multiple breakpoints (e.g.,
2101 breakpoints on overloaded c++ functions).
2103 * The `rbreak' command now accepts a filename specification as part of
2104 its argument, limiting the functions selected by the regex to those
2105 in the specified file.
2107 * Support for remote debugging Windows and SymbianOS shared libraries
2108 from Unix hosts has been improved. Non Windows GDB builds now can
2109 understand target reported file names that follow MS-DOS based file
2110 system semantics, such as file names that include drive letters and
2111 use the backslash character as directory separator. This makes it
2112 possible to transparently use the "set sysroot" and "set
2113 solib-search-path" on Unix hosts to point as host copies of the
2114 target's shared libraries. See the new command "set
2115 target-file-system-kind" described below, and the "Commands to
2116 specify files" section in the user manual for more information.
2120 eval template, expressions...
2121 Convert the values of one or more expressions under the control
2122 of the string template to a command line, and call it.
2124 set target-file-system-kind unix|dos-based|auto
2125 show target-file-system-kind
2126 Set or show the assumed file system kind for target reported file
2129 save breakpoints <filename>
2130 Save all current breakpoint definitions to a file suitable for use
2131 in a later debugging session. To read the saved breakpoint
2132 definitions, use the `source' command.
2134 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2137 info static-tracepoint-markers
2138 Display information about static tracepoint markers in the target.
2140 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2141 Define a static tracepoint by probing a marker at the given
2142 function, line, address, or marker ID.
2146 Enable and disable observer mode.
2148 set may-write-registers on|off
2149 set may-write-memory on|off
2150 set may-insert-breakpoints on|off
2151 set may-insert-tracepoints on|off
2152 set may-insert-fast-tracepoints on|off
2153 set may-interrupt on|off
2154 Set individual permissions for GDB effects on the target. Note that
2155 some of these settings can have undesirable or surprising
2156 consequences, particularly when changed in the middle of a session.
2157 For instance, disabling the writing of memory can prevent
2158 breakpoints from being inserted, cause single-stepping to fail, or
2159 even crash your program, if you disable after breakpoints have been
2160 inserted. However, GDB should not crash.
2162 set record memory-query on|off
2163 show record memory-query
2164 Control whether to stop the inferior if memory changes caused
2165 by an instruction cannot be recorded.
2170 The disassemble command now supports "start,+length" form of two arguments.
2174 ** GDB now provides a new directory location, called the python directory,
2175 where Python scripts written for GDB can be installed. The location
2176 of that directory is <data-directory>/python, where <data-directory>
2177 is the GDB data directory. For more details, see section `Scripting
2178 GDB using Python' in the manual.
2180 ** The GDB Python API now has access to breakpoints, symbols, symbol
2181 tables, program spaces, inferiors, threads and frame's code blocks.
2182 Additionally, GDB Parameters can now be created from the API, and
2183 manipulated via set/show in the CLI.
2185 ** New functions gdb.target_charset, gdb.target_wide_charset,
2186 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2188 ** New exception gdb.GdbError.
2190 ** Pretty-printers are now also looked up in the current program space.
2192 ** Pretty-printers can now be individually enabled and disabled.
2194 ** GDB now looks for names of Python scripts to auto-load in a
2195 special section named `.debug_gdb_scripts', in addition to looking
2196 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2198 * Tracepoint actions were unified with breakpoint commands. In particular,
2199 there are no longer differences in "info break" output for breakpoints and
2200 tracepoints and the "commands" command can be used for both tracepoints and
2201 regular breakpoints.
2205 ARM Symbian arm*-*-symbianelf*
2207 * D language support.
2208 GDB now supports debugging programs written in the D programming
2211 * GDB now supports the extended ptrace interface for PowerPC which is
2212 available since Linux kernel version 2.6.34. This automatically enables
2213 any hardware breakpoints and additional hardware watchpoints available in
2214 the processor. The old ptrace interface exposes just one hardware
2215 watchpoint and no hardware breakpoints.
2217 * GDB is now able to use the Data Value Compare (DVC) register available on
2218 embedded PowerPC processors to implement in hardware simple watchpoint
2219 conditions of the form:
2221 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2223 This works in native GDB running on Linux kernels with the extended ptrace
2224 interface mentioned above.
2226 *** Changes in GDB 7.1
2230 ** Namespace Support
2232 GDB now supports importing of namespaces in C++. This enables the
2233 user to inspect variables from imported namespaces. Support for
2234 namepace aliasing has also been added. So, if a namespace is
2235 aliased in the current scope (e.g. namepace C=A; ) the user can
2236 print variables using the alias (e.g. (gdb) print C::x).
2240 All known bugs relating to the printing of virtual base class were
2241 fixed. It is now possible to call overloaded static methods using a
2246 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2247 and reinterpret_cast<> are now handled by the C++ expression parser.
2251 Xilinx MicroBlaze microblaze-*-*
2256 Xilinx MicroBlaze microblaze
2259 * Multi-program debugging.
2261 GDB now has support for multi-program (a.k.a. multi-executable or
2262 multi-exec) debugging. This allows for debugging multiple inferiors
2263 simultaneously each running a different program under the same GDB
2264 session. See "Debugging Multiple Inferiors and Programs" in the
2265 manual for more information. This implied some user visible changes
2266 in the multi-inferior support. For example, "info inferiors" now
2267 lists inferiors that are not running yet or that have exited
2268 already. See also "New commands" and "New options" below.
2270 * New tracing features
2272 GDB's tracepoint facility now includes several new features:
2274 ** Trace state variables
2276 GDB tracepoints now include support for trace state variables, which
2277 are variables managed by the target agent during a tracing
2278 experiment. They are useful for tracepoints that trigger each
2279 other, so for instance one tracepoint can count hits in a variable,
2280 and then a second tracepoint has a condition that is true when the
2281 count reaches a particular value. Trace state variables share the
2282 $-syntax of GDB convenience variables, and can appear in both
2283 tracepoint actions and condition expressions. Use the "tvariable"
2284 command to create, and "info tvariables" to view; see "Trace State
2285 Variables" in the manual for more detail.
2289 GDB now includes an option for defining fast tracepoints, which
2290 targets may implement more efficiently, such as by installing a jump
2291 into the target agent rather than a trap instruction. The resulting
2292 speedup can be by two orders of magnitude or more, although the
2293 tradeoff is that some program locations on some target architectures
2294 might not allow fast tracepoint installation, for instance if the
2295 instruction to be replaced is shorter than the jump. To request a
2296 fast tracepoint, use the "ftrace" command, with syntax identical to
2297 the regular trace command.
2299 ** Disconnected tracing
2301 It is now possible to detach GDB from the target while it is running
2302 a trace experiment, then reconnect later to see how the experiment
2303 is going. In addition, a new variable disconnected-tracing lets you
2304 tell the target agent whether to continue running a trace if the
2305 connection is lost unexpectedly.
2309 GDB now has the ability to save the trace buffer into a file, and
2310 then use that file as a target, similarly to you can do with
2311 corefiles. You can select trace frames, print data that was
2312 collected in them, and use tstatus to display the state of the
2313 tracing run at the moment that it was saved. To create a trace
2314 file, use "tsave <filename>", and to use it, do "target tfile
2317 ** Circular trace buffer
2319 You can ask the target agent to handle the trace buffer as a
2320 circular buffer, discarding the oldest trace frames to make room for
2321 newer ones, by setting circular-trace-buffer to on. This feature may
2322 not be available for all target agents.
2327 The disassemble command, when invoked with two arguments, now requires
2328 the arguments to be comma-separated.
2331 The info variables command now displays variable definitions. Files
2332 which only declare a variable are not shown.
2335 The source command is now capable of sourcing Python scripts.
2336 This feature is dependent on the debugger being build with Python
2339 Related to this enhancement is also the introduction of a new command
2340 "set script-extension" (see below).
2342 * New commands (for set/show, see "New options" below)
2344 record save [<FILENAME>]
2345 Save a file (in core file format) containing the process record
2346 execution log for replay debugging at a later time.
2348 record restore <FILENAME>
2349 Restore the process record execution log that was saved at an
2350 earlier time, for replay debugging.
2352 add-inferior [-copies <N>] [-exec <FILENAME>]
2355 clone-inferior [-copies <N>] [ID]
2356 Make a new inferior ready to execute the same program another
2357 inferior has loaded.
2362 maint info program-spaces
2363 List the program spaces loaded into GDB.
2365 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2366 show remote interrupt-sequence
2367 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2368 as the sequence to the remote target in order to interrupt the execution.
2369 Ctrl-C is a default. Some system prefers BREAK which is high level of
2370 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2371 Magic SysRq g. It is BREAK signal and character 'g'.
2373 set remote interrupt-on-connect [on | off]
2374 show remote interrupt-on-connect
2375 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2376 remote target when gdb connects to it. This is needed when you debug
2379 set remotebreak [on | off]
2381 Deprecated. Use "set/show remote interrupt-sequence" instead.
2383 tvariable $NAME [ = EXP ]
2384 Create or modify a trace state variable.
2387 List trace state variables and their values.
2389 delete tvariable $NAME ...
2390 Delete one or more trace state variables.
2393 Evaluate the given expressions without collecting anything into the
2394 trace buffer. (Valid in tracepoint actions only.)
2396 ftrace FN / FILE:LINE / *ADDR
2397 Define a fast tracepoint at the given function, line, or address.
2399 * New expression syntax
2401 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2402 GDB now parses 0b101010 identically with 42.
2406 set follow-exec-mode new|same
2407 show follow-exec-mode
2408 Control whether GDB reuses the same inferior across an exec call or
2409 creates a new one. This is useful to be able to restart the old
2410 executable after the inferior having done an exec call.
2412 set default-collect EXPR, ...
2413 show default-collect
2414 Define a list of expressions to be collected at each tracepoint.
2415 This is a useful way to ensure essential items are not overlooked,
2416 such as registers or a critical global variable.
2418 set disconnected-tracing
2419 show disconnected-tracing
2420 If set to 1, the target is instructed to continue tracing if it
2421 loses its connection to GDB. If 0, the target is to stop tracing
2424 set circular-trace-buffer
2425 show circular-trace-buffer
2426 If set to on, the target is instructed to use a circular trace buffer
2427 and discard the oldest trace frames instead of stopping the trace due
2428 to a full trace buffer. If set to off, the trace stops when the buffer
2429 fills up. Some targets may not support this.
2431 set script-extension off|soft|strict
2432 show script-extension
2433 If set to "off", the debugger does not perform any script language
2434 recognition, and all sourced files are assumed to be GDB scripts.
2435 If set to "soft" (the default), files are sourced according to
2436 filename extension, falling back to GDB scripts if the first
2438 If set to "strict", files are sourced according to filename extension.
2440 set ada trust-PAD-over-XVS on|off
2441 show ada trust-PAD-over-XVS
2442 If off, activate a workaround against a bug in the debugging information
2443 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2444 the GCC sources for more information about the GNAT encoding and
2445 PAD types in particular). It is always safe to set this option to
2446 off, but this introduces a slight performance penalty. The default
2449 * Python API Improvements
2451 ** GDB provides the new class gdb.LazyString. This is useful in
2452 some pretty-printing cases. The new method gdb.Value.lazy_string
2453 provides a simple way to create objects of this type.
2455 ** The fields returned by gdb.Type.fields now have an
2456 `is_base_class' attribute.
2458 ** The new method gdb.Type.range returns the range of an array type.
2460 ** The new method gdb.parse_and_eval can be used to parse and
2461 evaluate an expression.
2463 * New remote packets
2466 Define a trace state variable.
2469 Get the current value of a trace state variable.
2472 Set desired tracing behavior upon disconnection.
2475 Set the trace buffer to be linear or circular.
2478 Get data about the tracepoints currently in use.
2482 Process record now works correctly with hardware watchpoints.
2484 Multiple bug fixes have been made to the mips-irix port, making it
2485 much more reliable. In particular:
2486 - Debugging threaded applications is now possible again. Previously,
2487 GDB would hang while starting the program, or while waiting for
2488 the program to stop at a breakpoint.
2489 - Attaching to a running process no longer hangs.
2490 - An error occurring while loading a core file has been fixed.
2491 - Changing the value of the PC register now works again. This fixes
2492 problems observed when using the "jump" command, or when calling
2493 a function from GDB, or even when assigning a new value to $pc.
2494 - With the "finish" and "return" commands, the return value for functions
2495 returning a small array is now correctly printed.
2496 - It is now possible to break on shared library code which gets executed
2497 during a shared library init phase (code executed while executing
2498 their .init section). Previously, the breakpoint would have no effect.
2499 - GDB is now able to backtrace through the signal handler for
2500 non-threaded programs.
2502 PIE (Position Independent Executable) programs debugging is now supported.
2503 This includes debugging execution of PIC (Position Independent Code) shared
2504 libraries although for that, it should be possible to run such libraries as an
2507 *** Changes in GDB 7.0
2509 * GDB now has an interface for JIT compilation. Applications that
2510 dynamically generate code can create symbol files in memory and register
2511 them with GDB. For users, the feature should work transparently, and
2512 for JIT developers, the interface is documented in the GDB manual in the
2513 "JIT Compilation Interface" chapter.
2515 * Tracepoints may now be conditional. The syntax is as for
2516 breakpoints; either an "if" clause appended to the "trace" command,
2517 or the "condition" command is available. GDB sends the condition to
2518 the target for evaluation using the same bytecode format as is used
2519 for tracepoint actions.
2521 * The disassemble command now supports: an optional /r modifier, print the
2522 raw instructions in hex as well as in symbolic form, and an optional /m
2523 modifier to print mixed source+assembly.
2525 * Process record and replay
2527 In a architecture environment that supports ``process record and
2528 replay'', ``process record and replay'' target can record a log of
2529 the process execution, and replay it with both forward and reverse
2532 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2533 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2534 set execution-direction {forward|reverse}, for targets that support
2537 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2538 feature is available with a native GDB running on kernel version
2541 * GDB now has support for multi-byte and wide character sets on the
2542 target. Strings whose character type is wchar_t, char16_t, or
2543 char32_t are now correctly printed. GDB supports wide- and unicode-
2544 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2545 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2546 `printf'. This feature requires iconv to work properly; if your
2547 system does not have a working iconv, GDB can use GNU libiconv. See
2548 the installation instructions for more information.
2550 * GDB now supports automatic retrieval of shared library files from
2551 remote targets. To use this feature, specify a system root that begins
2552 with the `remote:' prefix, either via the `set sysroot' command or via
2553 the `--with-sysroot' configure-time option.
2555 * "info sharedlibrary" now takes an optional regex of libraries to show,
2556 and it now reports if a shared library has no debugging information.
2558 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2559 now complete on file names.
2561 * When completing in expressions, gdb will attempt to limit
2562 completions to allowable structure or union fields, where appropriate.
2563 For instance, consider:
2565 # struct example { int f1; double f2; };
2566 # struct example variable;
2569 If the user types TAB at the end of this command line, the available
2570 completions will be "f1" and "f2".
2572 * Inlined functions are now supported. They show up in backtraces, and
2573 the "step", "next", and "finish" commands handle them automatically.
2575 * GDB now supports the token-splicing (##) and stringification (#)
2576 operators when expanding macros. It also supports variable-arity
2579 * GDB now supports inspecting extra signal information, exported by
2580 the new $_siginfo convenience variable. The feature is currently
2581 implemented on linux ARM, i386 and amd64.
2583 * GDB can now display the VFP floating point registers and NEON vector
2584 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2585 can provide these registers (requires Linux 2.6.30 or later). Remote
2586 and simulator targets may also provide them.
2588 * New remote packets
2591 Search memory for a sequence of bytes.
2594 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2595 operation over reliable transport links. Use of this packet is
2596 controlled by the `set remote noack-packet' command.
2599 Kill the process with the specified process ID. Use this in preference
2600 to `k' when multiprocess protocol extensions are supported.
2603 Obtains additional operating system information
2607 Read or write additional signal information.
2609 * Removed remote protocol undocumented extension
2611 An undocumented extension to the remote protocol's `S' stop reply
2612 packet that permited the stub to pass a process id was removed.
2613 Remote servers should use the `T' stop reply packet instead.
2615 * GDB now supports multiple function calling conventions according to the
2616 DWARF-2 DW_AT_calling_convention function attribute.
2618 * The SH target utilizes the aforementioned change to distinguish between gcc
2619 and Renesas calling convention. It also adds the new CLI commands
2620 `set/show sh calling-convention'.
2622 * GDB can now read compressed debug sections, as produced by GNU gold
2623 with the --compress-debug-sections=zlib flag.
2625 * 64-bit core files are now supported on AIX.
2627 * Thread switching is now supported on Tru64.
2629 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2630 which will be allocated using malloc later in program execution.
2632 * The qXfer:libraries:read remote procotol packet now allows passing a
2633 list of section offsets.
2635 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2636 conditions handling signals delivered during attach or thread creation
2637 have also been fixed.
2639 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2640 From the user's standpoint, all unqualified instances of True and False
2641 are treated as the standard definitions, regardless of context.
2643 * GDB now parses C++ symbol and type names more flexibly. For
2646 template<typename T> class C { };
2649 GDB will now correctly handle all of:
2651 ptype C<char const *>
2652 ptype C<char const*>
2653 ptype C<const char *>
2654 ptype C<const char*>
2656 * New features in the GDB remote stub, gdbserver
2658 - The "--wrapper" command-line argument tells gdbserver to use a
2659 wrapper program to launch programs for debugging.
2661 - On PowerPC and S/390 targets, it is now possible to use a single
2662 gdbserver executable to debug both 32-bit and 64-bit programs.
2663 (This requires gdbserver itself to be built as a 64-bit executable.)
2665 - gdbserver uses the new noack protocol mode for TCP connections to
2666 reduce communications latency, if also supported and enabled in GDB.
2668 - Support for the sparc64-linux-gnu target is now included in
2671 - The amd64-linux build of gdbserver now supports debugging both
2672 32-bit and 64-bit programs.
2674 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2675 now support hardware watchpoints, and will use them automatically
2680 GDB now has support for scripting using Python. Whether this is
2681 available is determined at configure time.
2683 New GDB commands can now be written in Python.
2685 * Ada tasking support
2687 Ada tasks can now be inspected in GDB. The following commands have
2691 Print the list of Ada tasks.
2693 Print detailed information about task number N.
2695 Print the task number of the current task.
2697 Switch the context of debugging to task number N.
2699 * Support for user-defined prefixed commands. The "define" command can
2700 add new commands to existing prefixes, e.g. "target".
2702 * Multi-inferior, multi-process debugging.
2704 GDB now has generalized support for multi-inferior debugging. See
2705 "Debugging Multiple Inferiors" in the manual for more information.
2706 Although availability still depends on target support, the command
2707 set is more uniform now. The GNU/Linux specific multi-forks support
2708 has been migrated to this new framework. This implied some user
2709 visible changes; see "New commands" and also "Removed commands"
2712 * Target descriptions can now describe the target OS ABI. See the
2713 "Target Description Format" section in the user manual for more
2716 * Target descriptions can now describe "compatible" architectures
2717 to indicate that the target can execute applications for a different
2718 architecture in addition to those for the main target architecture.
2719 See the "Target Description Format" section in the user manual for
2722 * Multi-architecture debugging.
2724 GDB now includes general supports for debugging applications on
2725 hybrid systems that use more than one single processor architecture
2726 at the same time. Each such hybrid architecture still requires
2727 specific support to be added. The only hybrid architecture supported
2728 in this version of GDB is the Cell Broadband Engine.
2730 * GDB now supports integrated debugging of Cell/B.E. applications that
2731 use both the PPU and SPU architectures. To enable support for hybrid
2732 Cell/B.E. debugging, you need to configure GDB to support both the
2733 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2734 --enable-targets configure option.
2736 * Non-stop mode debugging.
2738 For some targets, GDB now supports an optional mode of operation in
2739 which you can examine stopped threads while other threads continue
2740 to execute freely. This is referred to as non-stop mode, with the
2741 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2742 section in the user manual for more information.
2744 To be able to support remote non-stop debugging, a remote stub needs
2745 to implement the non-stop mode remote protocol extensions, as
2746 described in the "Remote Non-Stop" section of the user manual. The
2747 GDB remote stub, gdbserver, has been adjusted to support these
2748 extensions on linux targets.
2750 * New commands (for set/show, see "New options" below)
2752 catch syscall [NAME(S) | NUMBER(S)]
2753 Catch system calls. Arguments, which should be names of system
2754 calls or their numbers, mean catch only those syscalls. Without
2755 arguments, every syscall will be caught. When the inferior issues
2756 any of the specified syscalls, GDB will stop and announce the system
2757 call, both when it is called and when its call returns. This
2758 feature is currently available with a native GDB running on the
2759 Linux Kernel, under the following architectures: x86, x86_64,
2760 PowerPC and PowerPC64.
2762 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2764 Search memory for a sequence of bytes.
2766 maint set python print-stack
2767 maint show python print-stack
2768 Show a stack trace when an error is encountered in a Python script.
2771 Invoke CODE by passing it to the Python interpreter.
2776 These allow macros to be defined, undefined, and listed
2780 Show operating system information about processes.
2783 List the inferiors currently under GDB's control.
2786 Switch focus to inferior number NUM.
2789 Detach from inferior number NUM.
2792 Kill inferior number NUM.
2796 set spu stop-on-load
2797 show spu stop-on-load
2798 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2800 set spu auto-flush-cache
2801 show spu auto-flush-cache
2802 Control whether to automatically flush the software-managed cache
2803 during Cell/B.E. debugging.
2805 set sh calling-convention
2806 show sh calling-convention
2807 Control the calling convention used when calling SH target functions.
2810 show debug timestamp
2811 Control display of timestamps with GDB debugging output.
2813 set disassemble-next-line
2814 show disassemble-next-line
2815 Control display of disassembled source lines or instructions when
2818 set remote noack-packet
2819 show remote noack-packet
2820 Set/show the use of remote protocol QStartNoAckMode packet. See above
2821 under "New remote packets."
2823 set remote query-attached-packet
2824 show remote query-attached-packet
2825 Control use of remote protocol `qAttached' (query-attached) packet.
2827 set remote read-siginfo-object
2828 show remote read-siginfo-object
2829 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2832 set remote write-siginfo-object
2833 show remote write-siginfo-object
2834 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2837 set remote reverse-continue
2838 show remote reverse-continue
2839 Control use of remote protocol 'bc' (reverse-continue) packet.
2841 set remote reverse-step
2842 show remote reverse-step
2843 Control use of remote protocol 'bs' (reverse-step) packet.
2845 set displaced-stepping
2846 show displaced-stepping
2847 Control displaced stepping mode. Displaced stepping is a way to
2848 single-step over breakpoints without removing them from the debuggee.
2849 Also known as "out-of-line single-stepping".
2852 show debug displaced
2853 Control display of debugging info for displaced stepping.
2855 maint set internal-error
2856 maint show internal-error
2857 Control what GDB does when an internal error is detected.
2859 maint set internal-warning
2860 maint show internal-warning
2861 Control what GDB does when an internal warning is detected.
2866 Use a wrapper program to launch programs for debugging.
2868 set multiple-symbols (all|ask|cancel)
2869 show multiple-symbols
2870 The value of this variable can be changed to adjust the debugger behavior
2871 when an expression or a breakpoint location contains an ambiguous symbol
2872 name (an overloaded function name, for instance).
2874 set breakpoint always-inserted
2875 show breakpoint always-inserted
2876 Keep breakpoints always inserted in the target, as opposed to inserting
2877 them when resuming the target, and removing them when the target stops.
2878 This option can improve debugger performance on slow remote targets.
2880 set arm fallback-mode (arm|thumb|auto)
2881 show arm fallback-mode
2882 set arm force-mode (arm|thumb|auto)
2884 These commands control how ARM GDB determines whether instructions
2885 are ARM or Thumb. The default for both settings is auto, which uses
2886 the current CPSR value for instructions without symbols; previous
2887 versions of GDB behaved as if "set arm fallback-mode arm".
2889 set disable-randomization
2890 show disable-randomization
2891 Standalone programs run with the virtual address space randomization enabled
2892 by default on some platforms. This option keeps the addresses stable across
2893 multiple debugging sessions.
2897 Control whether other threads are stopped or not when some thread hits
2902 Requests that asynchronous execution is enabled in the target, if available.
2903 In this case, it's possible to resume target in the background, and interact
2904 with GDB while the target is running. "show target-async" displays the
2905 current state of asynchronous execution of the target.
2907 set target-wide-charset
2908 show target-wide-charset
2909 The target-wide-charset is the name of the character set that GDB
2910 uses when printing characters whose type is wchar_t.
2912 set tcp auto-retry (on|off)
2914 set tcp connect-timeout
2915 show tcp connect-timeout
2916 These commands allow GDB to retry failed TCP connections to a remote stub
2917 with a specified timeout period; this is useful if the stub is launched
2918 in parallel with GDB but may not be ready to accept connections immediately.
2920 set libthread-db-search-path
2921 show libthread-db-search-path
2922 Control list of directories which GDB will search for appropriate
2925 set schedule-multiple (on|off)
2926 show schedule-multiple
2927 Allow GDB to resume all threads of all processes or only threads of
2928 the current process.
2932 Use more aggressive caching for accesses to the stack. This improves
2933 performance of remote debugging (particularly backtraces) without
2934 affecting correctness.
2936 set interactive-mode (on|off|auto)
2937 show interactive-mode
2938 Control whether GDB runs in interactive mode (on) or not (off).
2939 When in interactive mode, GDB waits for the user to answer all
2940 queries. Otherwise, GDB does not wait and assumes the default
2941 answer. When set to auto (the default), GDB determines which
2942 mode to use based on the stdin settings.
2947 For program forks, this is replaced by the new more generic `info
2948 inferiors' command. To list checkpoints, you can still use the
2949 `info checkpoints' command, which was an alias for the `info forks'
2953 Replaced by the new `inferior' command. To switch between
2954 checkpoints, you can still use the `restart' command, which was an
2955 alias for the `fork' command.
2958 This is removed, since some targets don't have a notion of
2959 processes. To switch between processes, you can still use the
2960 `inferior' command using GDB's own inferior number.
2963 For program forks, this is replaced by the new more generic `kill
2964 inferior' command. To delete a checkpoint, you can still use the
2965 `delete checkpoint' command, which was an alias for the `delete
2969 For program forks, this is replaced by the new more generic `detach
2970 inferior' command. To detach a checkpoint, you can still use the
2971 `detach checkpoint' command, which was an alias for the `detach
2974 * New native configurations
2976 x86/x86_64 Darwin i[34567]86-*-darwin*
2978 x86_64 MinGW x86_64-*-mingw*
2982 Lattice Mico32 lm32-*
2983 x86 DICOS i[34567]86-*-dicos*
2984 x86_64 DICOS x86_64-*-dicos*
2987 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2988 (mingw32ce) debugging.
2994 These commands were actually not implemented on any target.
2996 *** Changes in GDB 6.8
2998 * New native configurations
3000 NetBSD/hppa hppa*-*netbsd*
3001 Xtensa GNU/Linux xtensa*-*-linux*
3005 NetBSD/hppa hppa*-*-netbsd*
3006 Xtensa GNU/Lunux xtensa*-*-linux*
3008 * Change in command line behavior -- corefiles vs. process ids.
3010 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3011 attaching to process NUMBER fails, GDB no longer attempts to open a
3012 core file named NUMBER. Attaching to a program using the -c option
3013 is no longer supported. Instead, use the '-p' or '--pid' options.
3015 * GDB can now be built as a native debugger for debugging Windows x86
3016 (mingw32) Portable Executable (PE) programs.
3018 * Pending breakpoints no longer change their number when their address
3021 * GDB now supports breakpoints with multiple locations,
3022 including breakpoints on C++ constructors, inside C++ templates,
3023 and in inlined functions.
3025 * GDB's ability to debug optimized code has been improved. GDB more
3026 accurately identifies function bodies and lexical blocks that occupy
3027 more than one contiguous range of addresses.
3029 * Target descriptions can now describe registers for PowerPC.
3031 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3032 registers on PowerPC targets.
3034 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3035 targets even when the libthread_db library is not available.
3037 * The GDB remote stub, gdbserver, now supports the new file transfer
3038 commands (remote put, remote get, and remote delete).
3040 * The GDB remote stub, gdbserver, now supports run and attach in
3041 extended-remote mode.
3043 * hppa*64*-*-hpux11* target broken
3044 The debugger is unable to start a program and fails with the following
3045 error: "Error trying to get information about dynamic linker".
3046 The gdb-6.7 release is also affected.
3048 * GDB now supports the --enable-targets= configure option to allow
3049 building a single GDB executable that supports multiple remote
3050 target architectures.
3052 * GDB now supports debugging C and C++ programs which use the
3053 Decimal Floating Point extension. In addition, the PowerPC target
3054 now has a set of pseudo-registers to inspect decimal float values
3055 stored in two consecutive float registers.
3057 * The -break-insert MI command can optionally create pending
3060 * Improved support for debugging Ada
3061 Many improvements to the Ada language support have been made. These
3063 - Better support for Ada2005 interface types
3064 - Improved handling of arrays and slices in general
3065 - Better support for Taft-amendment types
3066 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3068 - Improved command completion in Ada
3071 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3076 set print frame-arguments (all|scalars|none)
3077 show print frame-arguments
3078 The value of this variable can be changed to control which argument
3079 values should be printed by the debugger when displaying a frame.
3084 Transfer files to and from a remote target, and delete remote files.
3091 Transfer files to and from a remote target, and delete remote files.
3093 * New remote packets
3100 Open, close, read, write, and delete files on the remote system.
3103 Attach to an existing process on the remote system, in extended-remote
3107 Run a new process on the remote system, in extended-remote mode.
3109 *** Changes in GDB 6.7
3111 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3112 bfd, libiberty and opcodes, as revealed by static analysis donated by
3113 Coverity, Inc. (http://scan.coverity.com).
3115 * When looking up multiply-defined global symbols, GDB will now prefer the
3116 symbol definition in the current shared library if it was built using the
3117 -Bsymbolic linker option.
3119 * When the Text User Interface (TUI) is not configured, GDB will now
3120 recognize the -tui command-line option and print a message that the TUI
3123 * The GDB remote stub, gdbserver, now has lower overhead for high
3124 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3126 * GDB for MIPS targets now autodetects whether a remote target provides
3127 32-bit or 64-bit register values.
3129 * Support for C++ member pointers has been improved.
3131 * GDB now understands XML target descriptions, which specify the
3132 target's overall architecture. GDB can read a description from
3133 a local file or over the remote serial protocol.
3135 * Vectors of single-byte data use a new integer type which is not
3136 automatically displayed as character or string data.
3138 * The /s format now works with the print command. It displays
3139 arrays of single-byte integers and pointers to single-byte integers
3142 * Target descriptions can now describe target-specific registers,
3143 for architectures which have implemented the support (currently
3144 only ARM, M68K, and MIPS).
3146 * GDB and the GDB remote stub, gdbserver, now support the XScale
3149 * The GDB remote stub, gdbserver, has been updated to support
3150 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3151 has been rewritten to use the standard GDB remote protocol.
3153 * GDB can now step into C++ functions which are called through thunks.
3155 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3157 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3158 layout. It also supports a TextSeg= and DataSeg= response when only
3159 segment base addresses (rather than offsets) are available.
3161 * The /i format now outputs any trailing branch delay slot instructions
3162 immediately following the last instruction within the count specified.
3164 * The GDB remote protocol "T" stop reply packet now supports a
3165 "library" response. Combined with the new "qXfer:libraries:read"
3166 packet, this response allows GDB to debug shared libraries on targets
3167 where the operating system manages the list of loaded libraries (e.g.
3168 Windows and SymbianOS).
3170 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3171 (DLLs) on Windows and Windows CE targets.
3173 * GDB now supports a faster verification that a .debug file matches its binary
3174 according to its build-id signature, if the signature is present.
3180 Enable or disable hardware flow control (RTS/CTS) on the serial port
3181 when debugging using remote targets.
3183 set mem inaccessible-by-default
3184 show mem inaccessible-by-default
3185 If the target supplies a memory map, for instance via the remote
3186 protocol's "qXfer:memory-map:read" packet, setting this variable
3187 prevents GDB from accessing memory outside the memory map. This
3188 is useful for targets with memory mapped registers or which react
3189 badly to accesses of unmapped address space.
3191 set breakpoint auto-hw
3192 show breakpoint auto-hw
3193 If the target supplies a memory map, for instance via the remote
3194 protocol's "qXfer:memory-map:read" packet, setting this variable
3195 lets GDB use hardware breakpoints automatically for memory regions
3196 where it can not use software breakpoints. This covers both the
3197 "break" command and internal breakpoints used for other commands
3198 including "next" and "finish".
3201 catch exception unhandled
3202 Stop the program execution when Ada exceptions are raised.
3205 Stop the program execution when an Ada assertion failed.
3209 Set an alternate system root for target files. This is a more
3210 general version of "set solib-absolute-prefix", which is now
3211 an alias to "set sysroot".
3214 Provide extended SPU facility status information. This set of
3215 commands is available only when debugging the Cell/B.E. SPU
3218 * New native configurations
3220 OpenBSD/sh sh*-*openbsd*
3223 unset tdesc filename
3225 Use the specified local file as an XML target description, and do
3226 not query the target for its built-in description.
3230 OpenBSD/sh sh*-*-openbsd*
3231 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3232 Toshiba Media Processor mep-elf
3234 * New remote packets
3237 Ignore the specified signals; pass them directly to the debugged program
3238 without stopping other threads or reporting them to GDB.
3240 qXfer:features:read:
3241 Read an XML target description from the target, which describes its
3246 Read or write contents of an spufs file on the target system. These
3247 packets are available only on the Cell/B.E. SPU architecture.
3249 qXfer:libraries:read:
3250 Report the loaded shared libraries. Combined with new "T" packet
3251 response, this packet allows GDB to debug shared libraries on
3252 targets where the operating system manages the list of loaded
3253 libraries (e.g. Windows and SymbianOS).
3257 Support for these obsolete configurations has been removed.
3265 i[34567]86-*-lynxos*
3266 i[34567]86-*-netware*
3267 i[34567]86-*-sco3.2v5*
3268 i[34567]86-*-sco3.2v4*
3270 i[34567]86-*-sysv4.2*
3273 i[34567]86-*-unixware2*
3274 i[34567]86-*-unixware*
3283 * Other removed features
3290 Various m68k-only ROM monitors.
3297 Various Renesas ROM monitors and debugging interfaces for SH and
3302 Support for a Macraigor serial interface to on-chip debugging.
3303 GDB does not directly support the newer parallel or USB
3308 A debug information format. The predecessor to DWARF 2 and
3309 DWARF 3, which are still supported.
3311 Support for the HP aCC compiler on HP-UX/PA-RISC
3313 SOM-encapsulated symbolic debugging information, automatic
3314 invocation of pxdb, and the aCC custom C++ ABI. This does not
3315 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3316 with aCC can still be debugged on an assembly level.
3318 MIPS ".pdr" sections
3320 A MIPS-specific format used to describe stack frame layout
3321 in debugging information.
3325 GDB could work with an older version of Guile to debug
3326 the interpreter and Scheme programs running in it.
3328 set mips stack-arg-size
3329 set mips saved-gpreg-size
3331 Use "set mips abi" to control parameter passing for MIPS.
3333 *** Changes in GDB 6.6
3338 Cell Broadband Engine SPU spu-elf
3340 * GDB can now be configured as a cross-debugger targeting native Windows
3341 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3342 running on a Windows system over TCP/IP to debug Windows programs.
3344 * The GDB remote stub, gdbserver, has been updated to support Windows and
3345 Cygwin debugging. Both single-threaded and multi-threaded programs are
3348 * The "set trust-readonly-sections" command works again. This command was
3349 broken in GDB 6.3, 6.4, and 6.5.
3351 * The "load" command now supports writing to flash memory, if the remote
3352 stub provides the required support.
3354 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3355 longer requires symbolic debug information (e.g. DWARF-2).
3360 unset substitute-path
3361 show substitute-path
3362 Manage a list of substitution rules that GDB uses to rewrite the name
3363 of the directories where the sources are located. This can be useful
3364 for instance when the sources were moved to a different location
3365 between compilation and debugging.
3369 Print each CLI command as it is executed. Each command is prefixed with
3370 a number of `+' symbols representing the nesting depth.
3371 The source command now has a `-v' option to enable the same feature.
3375 The ARM Demon monitor support (RDP protocol, "target rdp").
3377 Kernel Object Display, an embedded debugging feature which only worked with
3378 an obsolete version of Cisco IOS.
3380 The 'set download-write-size' and 'show download-write-size' commands.
3382 * New remote packets
3385 Tell a stub about GDB client features, and request remote target features.
3386 The first feature implemented is PacketSize, which allows the target to
3387 specify the size of packets it can handle - to minimize the number of
3388 packets required and improve performance when connected to a remote
3392 Fetch an OS auxilliary vector from the remote stub. This packet is a
3393 more efficient replacement for qPart:auxv:read.
3395 qXfer:memory-map:read:
3396 Fetch a memory map from the remote stub, including information about
3397 RAM, ROM, and flash memory devices.
3402 Erase and program a flash memory device.
3404 * Removed remote packets
3407 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3408 used it, and only gdbserver implemented it.
3410 *** Changes in GDB 6.5
3414 Renesas M32C/M16C m32c-elf
3416 Morpho Technologies ms1 ms1-elf
3420 init-if-undefined Initialize a convenience variable, but
3421 only if it doesn't already have a value.
3423 The following commands are presently only implemented for native GNU/Linux:
3425 checkpoint Save a snapshot of the program state.
3427 restart <n> Return the program state to a
3428 previously saved state.
3430 info checkpoints List currently saved checkpoints.
3432 delete-checkpoint <n> Delete a previously saved checkpoint.
3434 set|show detach-on-fork Tell gdb whether to detach from a newly
3435 forked process, or to keep debugging it.
3437 info forks List forks of the user program that
3438 are available to be debugged.
3440 fork <n> Switch to debugging one of several
3441 forks of the user program that are
3442 available to be debugged.
3444 delete-fork <n> Delete a fork from the list of forks
3445 that are available to be debugged (and
3446 kill the forked process).
3448 detach-fork <n> Delete a fork from the list of forks
3449 that are available to be debugged (and
3450 allow the process to continue).
3454 Morpho Technologies ms2 ms1-elf
3456 * Improved Windows host support
3458 GDB now builds as a cross debugger hosted on i686-mingw32, including
3459 native console support, and remote communications using either
3460 network sockets or serial ports.
3462 * Improved Modula-2 language support
3464 GDB can now print most types in the Modula-2 syntax. This includes:
3465 basic types, set types, record types, enumerated types, range types,
3466 pointer types and ARRAY types. Procedure var parameters are correctly
3467 printed and hexadecimal addresses and character constants are also
3468 written in the Modula-2 syntax. Best results can be obtained by using
3469 GNU Modula-2 together with the -gdwarf-2 command line option.
3473 The ARM rdi-share module.
3475 The Netware NLM debug server.
3477 *** Changes in GDB 6.4
3479 * New native configurations
3481 OpenBSD/arm arm*-*-openbsd*
3482 OpenBSD/mips64 mips64-*-openbsd*
3486 Morpho Technologies ms1 ms1-elf
3488 * New command line options
3490 --batch-silent As for --batch, but totally silent.
3491 --return-child-result The debugger will exist with the same value
3492 the child (debugged) program exited with.
3493 --eval-command COMMAND, -ex COMMAND
3494 Execute a single GDB CLI command. This may be
3495 specified multiple times and in conjunction
3496 with the --command (-x) option.
3498 * Deprecated commands removed
3500 The following commands, that were deprecated in 2000, have been
3504 set|show arm disassembly-flavor set|show arm disassembler
3505 othernames set arm disassembler
3506 set|show remotedebug set|show debug remote
3507 set|show archdebug set|show debug arch
3508 set|show eventdebug set|show debug event
3511 * New BSD user-level threads support
3513 It is now possible to debug programs using the user-level threads
3514 library on OpenBSD and FreeBSD. Currently supported (target)
3517 FreeBSD/amd64 x86_64-*-freebsd*
3518 FreeBSD/i386 i386-*-freebsd*
3519 OpenBSD/i386 i386-*-openbsd*
3521 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3522 are not yet supported.
3524 * New support for Matsushita MN10300 w/sim added
3525 (Work in progress). mn10300-elf.
3527 * REMOVED configurations and files
3529 VxWorks and the XDR protocol *-*-vxworks
3530 Motorola MCORE mcore-*-*
3531 National Semiconductor NS32000 ns32k-*-*
3533 * New "set print array-indexes" command
3535 After turning this setting "on", GDB prints the index of each element
3536 when displaying arrays. The default is "off" to preserve the previous
3539 * VAX floating point support
3541 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3543 * User-defined command support
3545 In addition to using $arg0..$arg9 for argument passing, it is now possible
3546 to use $argc to determine now many arguments have been passed. See the
3547 section on user-defined commands in the user manual for more information.
3549 *** Changes in GDB 6.3:
3551 * New command line option
3553 GDB now accepts -l followed by a number to set the timeout for remote
3556 * GDB works with GCC -feliminate-dwarf2-dups
3558 GDB now supports a more compact representation of DWARF-2 debug
3559 information using DW_FORM_ref_addr references. These are produced
3560 by GCC with the option -feliminate-dwarf2-dups and also by some
3561 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3562 to use -feliminate-dwarf2-dups.
3564 * Internationalization
3566 When supported by the host system, GDB will be built with
3567 internationalization (libintl). The task of marking up the sources is
3568 continued, we're looking forward to our first translation.
3572 Initial support for debugging programs compiled with the GNAT
3573 implementation of the Ada programming language has been integrated
3574 into GDB. In this release, support is limited to expression evaluation.
3576 * New native configurations
3578 GNU/Linux/m32r m32r-*-linux-gnu
3582 GDB's remote protocol now includes support for the 'p' packet. This
3583 packet is used to fetch individual registers from a remote inferior.
3585 * END-OF-LIFE registers[] compatibility module
3587 GDB's internal register infrastructure has been completely rewritten.
3588 The new infrastructure making possible the implementation of key new
3589 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3592 GDB 6.3 will be the last release to include the the registers[]
3593 compatibility module that allowed out-of-date configurations to
3594 continue to work. This change directly impacts the following
3604 powerpc bdm protocol
3606 Unless there is activity to revive these configurations, they will be
3607 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3609 * OBSOLETE configurations and files
3611 Configurations that have been declared obsolete in this release have
3612 been commented out. Unless there is activity to revive these
3613 configurations, the next release of GDB will have their sources
3614 permanently REMOVED.
3623 *** Changes in GDB 6.2.1:
3625 * MIPS `break main; run' gave an heuristic-fence-post warning
3627 When attempting to run even a simple program, a warning about
3628 heuristic-fence-post being hit would be reported. This problem has
3631 * MIPS IRIX 'long double' crashed GDB
3633 When examining a long double variable, GDB would get a segmentation
3634 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3635 IRIX long double values).
3639 A bug in the VAX stack code was causing problems with the "next"
3640 command. This problem has been fixed.
3642 *** Changes in GDB 6.2:
3644 * Fix for ``many threads''
3646 On GNU/Linux systems that use the NPTL threads library, a program
3647 rapidly creating and deleting threads would confuse GDB leading to the
3650 ptrace: No such process.
3651 thread_db_get_info: cannot get thread info: generic error
3653 This problem has been fixed.
3655 * "-async" and "-noasync" options removed.
3657 Support for the broken "-noasync" option has been removed (it caused
3660 * New ``start'' command.
3662 This command runs the program until the begining of the main procedure.
3664 * New BSD Kernel Data Access Library (libkvm) interface
3666 Using ``target kvm'' it is now possible to debug kernel core dumps and
3667 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3668 platforms. Currently supported (native-only) configurations are:
3670 FreeBSD/amd64 x86_64-*-freebsd*
3671 FreeBSD/i386 i?86-*-freebsd*
3672 NetBSD/i386 i?86-*-netbsd*
3673 NetBSD/m68k m68*-*-netbsd*
3674 NetBSD/sparc sparc-*-netbsd*
3675 OpenBSD/amd64 x86_64-*-openbsd*
3676 OpenBSD/i386 i?86-*-openbsd*
3677 OpenBSD/m68k m68*-openbsd*
3678 OpenBSD/sparc sparc-*-openbsd*
3680 * Signal trampoline code overhauled
3682 Many generic problems with GDB's signal handling code have been fixed.
3683 These include: backtraces through non-contiguous stacks; recognition
3684 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3685 call; backtrace through a signal trampoline; step into and out of
3686 signal handlers; and single-stepping in the signal trampoline.
3688 Please note that kernel bugs are a limiting factor here. These
3689 features have been shown to work on an s390 GNU/Linux system that
3690 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3692 * Cygwin support for DWARF 2 added.
3694 * New native configurations
3696 GNU/Linux/hppa hppa*-*-linux*
3697 OpenBSD/hppa hppa*-*-openbsd*
3698 OpenBSD/m68k m68*-*-openbsd*
3699 OpenBSD/m88k m88*-*-openbsd*
3700 OpenBSD/powerpc powerpc-*-openbsd*
3701 NetBSD/vax vax-*-netbsd*
3702 OpenBSD/vax vax-*-openbsd*
3704 * END-OF-LIFE frame compatibility module
3706 GDB's internal frame infrastructure has been completely rewritten.
3707 The new infrastructure making it possible to support key new features
3708 including DWARF 2 Call Frame Information. To aid in the task of
3709 migrating old configurations to this new infrastructure, a
3710 compatibility module, that allowed old configurations to continue to
3711 work, was also included.
3713 GDB 6.2 will be the last release to include this frame compatibility
3714 module. This change directly impacts the following configurations:
3724 Unless there is activity to revive these configurations, they will be
3725 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3727 * REMOVED configurations and files
3729 Sun 3, running SunOS 3 m68*-*-sunos3*
3730 Sun 3, running SunOS 4 m68*-*-sunos4*
3731 Sun 2, running SunOS 3 m68000-*-sunos3*
3732 Sun 2, running SunOS 4 m68000-*-sunos4*
3733 Motorola 680x0 running LynxOS m68*-*-lynxos*
3734 AT&T 3b1/Unix pc m68*-att-*
3735 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3736 decstation mips-dec-* mips-little-*
3737 riscos mips-*-riscos* mips-*-sysv*
3738 sonymips mips-sony-*
3739 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3741 *** Changes in GDB 6.1.1:
3743 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3745 The TUI (Text-mode User Interface) is now built as part of a default
3746 GDB configuration. It is enabled by either selecting the TUI with the
3747 command line option "-i=tui" or by running the separate "gdbtui"
3748 program. For more information on the TUI, see the manual "Debugging
3751 * Pending breakpoint support (also included in GDB 6.1)
3753 Support has been added to allow you to specify breakpoints in shared
3754 libraries that have not yet been loaded. If a breakpoint location
3755 cannot be found, and the "breakpoint pending" option is set to auto,
3756 GDB queries you if you wish to make the breakpoint pending on a future
3757 shared-library load. If and when GDB resolves the breakpoint symbol,
3758 the pending breakpoint is removed as one or more regular breakpoints
3761 Pending breakpoints are very useful for GCJ Java debugging.
3763 * Fixed ISO-C build problems
3765 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3766 non ISO-C code that stopped them being built using a more strict ISO-C
3767 compiler (e.g., IBM's C compiler).
3769 * Fixed build problem on IRIX 5
3771 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3772 wasn't able to compile compile on an IRIX 5 system.
3774 * Added execute permission to gdb/gdbserver/configure
3776 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3777 permission. This bug would cause configure to fail on a number of
3778 systems (Solaris, IRIX). Ref: server/519.
3780 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3782 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3783 has been updated to use constant array sizes.
3785 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3787 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3788 its generated DWARF Call Frame Info. This encoding was causing GDB to
3789 panic, that panic has been fixed. Ref: gdb/1628.
3791 * Fixed a problem when examining parameters in shared library code.
3793 When examining parameters in optimized shared library code generated
3794 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3795 not available''. GDB now correctly displays the variable's value.
3797 *** Changes in GDB 6.1:
3799 * Removed --with-mmalloc
3801 Support for the mmalloc memory manager has been removed, as it
3802 conflicted with the internal gdb byte cache.
3804 * Changes in AMD64 configurations
3806 The AMD64 target now includes the %cs and %ss registers. As a result
3807 the AMD64 remote protocol has changed; this affects the floating-point
3808 and SSE registers. If you rely on those registers for your debugging,
3809 you should upgrade gdbserver on the remote side.
3811 * Revised SPARC target
3813 The SPARC target has been completely revised, incorporating the
3814 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3815 support for LynxOS and SunOS 4 has been dropped. Calling functions
3816 from within GDB on operating systems with a non-executable stack
3817 (Solaris, OpenBSD) now works.
3821 GDB has a new C++ demangler which does a better job on the mangled
3822 names generated by current versions of g++. It also runs faster, so
3823 with this and other changes gdb should now start faster on large C++
3826 * DWARF 2 Location Expressions
3828 GDB support for location expressions has been extended to support function
3829 arguments and frame bases. Older versions of GDB could crash when they
3832 * C++ nested types and namespaces
3834 GDB's support for nested types and namespaces in C++ has been
3835 improved, especially if you use the DWARF 2 debugging format. (This
3836 is the default for recent versions of GCC on most platforms.)
3837 Specifically, if you have a class "Inner" defined within a class or
3838 namespace "Outer", then GDB realizes that the class's name is
3839 "Outer::Inner", not simply "Inner". This should greatly reduce the
3840 frequency of complaints about not finding RTTI symbols. In addition,
3841 if you are stopped at inside of a function defined within a namespace,
3842 GDB modifies its name lookup accordingly.
3844 * New native configurations
3846 NetBSD/amd64 x86_64-*-netbsd*
3847 OpenBSD/amd64 x86_64-*-openbsd*
3848 OpenBSD/alpha alpha*-*-openbsd*
3849 OpenBSD/sparc sparc-*-openbsd*
3850 OpenBSD/sparc64 sparc64-*-openbsd*
3852 * New debugging protocols
3854 M32R with SDI protocol m32r-*-elf*
3856 * "set prompt-escape-char" command deleted.
3858 The command "set prompt-escape-char" has been deleted. This command,
3859 and its very obscure effet on GDB's prompt, was never documented,
3860 tested, nor mentioned in the NEWS file.
3862 * OBSOLETE configurations and files
3864 Configurations that have been declared obsolete in this release have
3865 been commented out. Unless there is activity to revive these
3866 configurations, the next release of GDB will have their sources
3867 permanently REMOVED.
3869 Sun 3, running SunOS 3 m68*-*-sunos3*
3870 Sun 3, running SunOS 4 m68*-*-sunos4*
3871 Sun 2, running SunOS 3 m68000-*-sunos3*
3872 Sun 2, running SunOS 4 m68000-*-sunos4*
3873 Motorola 680x0 running LynxOS m68*-*-lynxos*
3874 AT&T 3b1/Unix pc m68*-att-*
3875 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3876 decstation mips-dec-* mips-little-*
3877 riscos mips-*-riscos* mips-*-sysv*
3878 sonymips mips-sony-*
3879 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3881 * REMOVED configurations and files
3883 SGI Irix-4.x mips-sgi-irix4 or iris4
3884 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3885 Z8000 simulator z8k-zilog-none or z8ksim
3886 Matsushita MN10200 w/simulator mn10200-*-*
3887 H8/500 simulator h8500-hitachi-hms or h8500hms
3888 HP/PA running BSD hppa*-*-bsd*
3889 HP/PA running OSF/1 hppa*-*-osf*
3890 HP/PA Pro target hppa*-*-pro*
3891 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3892 386BSD i[3456]86-*-bsd*
3893 Sequent family i[3456]86-sequent-sysv4*
3894 i[3456]86-sequent-sysv*
3895 i[3456]86-sequent-bsd*
3896 SPARC running LynxOS sparc-*-lynxos*
3897 SPARC running SunOS 4 sparc-*-sunos4*
3898 Tsqware Sparclet sparclet-*-*
3899 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3901 *** Changes in GDB 6.0:
3905 Support for debugging the Objective-C programming language has been
3906 integrated into GDB.
3908 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3910 DWARF 2's Call Frame Information makes available compiler generated
3911 information that more exactly describes the program's run-time stack.
3912 By using this information, GDB is able to provide more robust stack
3915 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3916 have been updated to use a new backtrace mechanism which includes
3917 DWARF 2 CFI support.
3921 GDB's remote protocol has been extended to include support for hosted
3922 file I/O (where the remote target uses GDB's file system). See GDB's
3923 remote protocol documentation for details.
3925 * All targets using the new architecture framework.
3927 All of GDB's targets have been updated to use the new internal
3928 architecture framework. The way is now open for future GDB releases
3929 to include cross-architecture native debugging support (i386 on amd64,
3932 * GNU/Linux's Thread Local Storage (TLS)
3934 GDB now includes support for for the GNU/Linux implementation of
3935 per-thread variables.
3937 * GNU/Linux's Native POSIX Thread Library (NPTL)
3939 GDB's thread code has been updated to work with either the new
3940 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3942 * Separate debug info.
3944 GDB, in conjunction with BINUTILS, now supports a mechanism for
3945 automatically loading debug information from a separate file. Instead
3946 of shipping full debug and non-debug versions of system libraries,
3947 system integrators can now instead ship just the stripped libraries
3948 and optional debug files.
3950 * DWARF 2 Location Expressions
3952 DWARF 2 Location Expressions allow the compiler to more completely
3953 describe the location of variables (even in optimized code) to the
3956 GDB now includes preliminary support for location expressions (support
3957 for DW_OP_piece is still missing).
3961 A number of long standing bugs that caused GDB to die while starting a
3962 Java application have been fixed. GDB's Java support is now
3963 considered "useable".
3965 * GNU/Linux support for fork, vfork, and exec.
3967 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3968 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3971 * GDB supports logging output to a file
3973 There are two new commands, "set logging" and "show logging", which can be
3974 used to capture GDB's output to a file.
3976 * The meaning of "detach" has changed for gdbserver
3978 The "detach" command will now resume the application, as documented. To
3979 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3982 * d10v, m68hc11 `regs' command deprecated
3984 The `info registers' command has been updated so that it displays the
3985 registers using a format identical to the old `regs' command.
3989 A new command, "maint set profile on/off", has been added. This command can
3990 be used to enable or disable profiling while running GDB, to profile a
3991 session or a set of commands. In addition there is a new configure switch,
3992 "--enable-profiling", which will cause GDB to be compiled with profiling
3993 data, for more informative profiling results.
3995 * Default MI syntax changed to "mi2".
3997 The default MI (machine interface) syntax, enabled by the command line
3998 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3999 "mi1", can be enabled by specifying the option "-i=mi1".
4001 Support for the original "mi0" syntax (included in GDB 5.0) has been
4004 Fix for gdb/192: removed extraneous space when displaying frame level.
4005 Fix for gdb/672: update changelist is now output in mi list format.
4006 Fix for gdb/702: a -var-assign that updates the value now shows up
4007 in a subsequent -var-update.
4009 * New native configurations.
4011 FreeBSD/amd64 x86_64-*-freebsd*
4013 * Multi-arched targets.
4015 HP/PA HPUX11 hppa*-*-hpux*
4016 Renesas M32R/D w/simulator m32r-*-elf*
4018 * OBSOLETE configurations and files
4020 Configurations that have been declared obsolete in this release have
4021 been commented out. Unless there is activity to revive these
4022 configurations, the next release of GDB will have their sources
4023 permanently REMOVED.
4025 Z8000 simulator z8k-zilog-none or z8ksim
4026 Matsushita MN10200 w/simulator mn10200-*-*
4027 H8/500 simulator h8500-hitachi-hms or h8500hms
4028 HP/PA running BSD hppa*-*-bsd*
4029 HP/PA running OSF/1 hppa*-*-osf*
4030 HP/PA Pro target hppa*-*-pro*
4031 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4032 Sequent family i[3456]86-sequent-sysv4*
4033 i[3456]86-sequent-sysv*
4034 i[3456]86-sequent-bsd*
4035 Tsqware Sparclet sparclet-*-*
4036 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4038 * REMOVED configurations and files
4041 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4042 IBM AIX PS/2 i[3456]86-*-aix
4043 i386 running Mach 3.0 i[3456]86-*-mach3*
4044 i386 running Mach i[3456]86-*-mach*
4045 i386 running OSF/1 i[3456]86-*osf1mk*
4046 HP/Apollo 68k Family m68*-apollo*-sysv*,
4048 m68*-hp-bsd*, m68*-hp-hpux*
4049 Argonaut Risc Chip (ARC) arc-*-*
4050 Mitsubishi D30V d30v-*-*
4051 Fujitsu FR30 fr30-*-elf*
4052 OS/9000 i[34]86-*-os9k
4053 I960 with MON960 i960-*-coff
4055 * MIPS $fp behavior changed
4057 The convenience variable $fp, for the MIPS, now consistently returns
4058 the address of the current frame's base. Previously, depending on the
4059 context, $fp could refer to either $sp or the current frame's base
4060 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4061 The GNU Source-Level Debugger''.
4063 *** Changes in GDB 5.3:
4065 * GNU/Linux shared library multi-threaded performance improved.
4067 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4068 `/proc', in preference to `ptrace' for memory reads. This may result
4069 in an improvement in the start-up time of multi-threaded, shared
4070 library applications when run under GDB. One GDB user writes: ``loads
4071 shared libs like mad''.
4073 * ``gdbserver'' now supports multi-threaded applications on some targets
4075 Support for debugging multi-threaded applications which use
4076 the GNU/Linux LinuxThreads package has been added for
4077 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4078 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4080 * GDB now supports C/C++ preprocessor macros.
4082 GDB now expands preprocessor macro invocations in C/C++ expressions,
4083 and provides various commands for showing macro definitions and how
4086 The new command `macro expand EXPRESSION' expands any macro
4087 invocations in expression, and shows the result.
4089 The new command `show macro MACRO-NAME' shows the definition of the
4090 macro named MACRO-NAME, and where it was defined.
4092 Most compilers don't include information about macros in the debugging
4093 information by default. In GCC 3.1, for example, you need to compile
4094 your program with the options `-gdwarf-2 -g3'. If the macro
4095 information is present in the executable, GDB will read it.
4097 * Multi-arched targets.
4099 DEC Alpha (partial) alpha*-*-*
4100 DEC VAX (partial) vax-*-*
4102 National Semiconductor NS32000 (partial) ns32k-*-*
4103 Motorola 68000 (partial) m68k-*-*
4104 Motorola MCORE mcore-*-*
4108 Fujitsu FRV architecture added by Red Hat frv*-*-*
4111 * New native configurations
4113 Alpha NetBSD alpha*-*-netbsd*
4114 SH NetBSD sh*-*-netbsdelf*
4115 MIPS NetBSD mips*-*-netbsd*
4116 UltraSPARC NetBSD sparc64-*-netbsd*
4118 * OBSOLETE configurations and files
4120 Configurations that have been declared obsolete in this release have
4121 been commented out. Unless there is activity to revive these
4122 configurations, the next release of GDB will have their sources
4123 permanently REMOVED.
4125 Mitsubishi D30V d30v-*-*
4126 OS/9000 i[34]86-*-os9k
4127 IBM AIX PS/2 i[3456]86-*-aix
4128 Fujitsu FR30 fr30-*-elf*
4129 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4130 Argonaut Risc Chip (ARC) arc-*-*
4131 i386 running Mach 3.0 i[3456]86-*-mach3*
4132 i386 running Mach i[3456]86-*-mach*
4133 i386 running OSF/1 i[3456]86-*osf1mk*
4134 HP/Apollo 68k Family m68*-apollo*-sysv*,
4136 m68*-hp-bsd*, m68*-hp-hpux*
4137 I960 with MON960 i960-*-coff
4139 * OBSOLETE languages
4141 CHILL, a Pascal like language used by telecommunications companies.
4143 * REMOVED configurations and files
4145 AMD 29k family via UDI a29k-amd-udi, udi29k
4146 A29K VxWorks a29k-*-vxworks
4147 AMD 29000 embedded, using EBMON a29k-none-none
4148 AMD 29000 embedded with COFF a29k-none-coff
4149 AMD 29000 embedded with a.out a29k-none-aout
4151 testsuite/gdb.hp/gdb.threads-hp/ directory
4153 * New command "set max-user-call-depth <nnn>"
4155 This command allows the user to limit the call depth of user-defined
4156 commands. The default is 1024.
4158 * Changes in FreeBSD/i386 native debugging.
4160 Support for the "generate-core-file" has been added.
4162 * New commands "dump", "append", and "restore".
4164 These commands allow data to be copied from target memory
4165 to a bfd-format or binary file (dump and append), and back
4166 from a file into memory (restore).
4168 * Improved "next/step" support on multi-processor Alpha Tru64.
4170 The previous single-step mechanism could cause unpredictable problems,
4171 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4172 of a software single-step mechanism prevents this.
4174 *** Changes in GDB 5.2.1:
4182 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4183 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4184 Fix, by Joel Brobecker imported from mainline.
4186 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4187 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4188 Fix, by Fred Fish, imported from mainline.
4190 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4191 Surprisingly enough, it works now.
4192 By Michal Ludvig, imported from mainline.
4194 i386 hardware watchpoint support:
4195 avoid misses on second run for some targets.
4196 By Pierre Muller, imported from mainline.
4198 *** Changes in GDB 5.2:
4200 * New command "set trust-readonly-sections on[off]".
4202 This command is a hint that tells gdb that read-only sections
4203 really are read-only (ie. that their contents will not change).
4204 In this mode, gdb will go to the object file rather than the
4205 target to read memory from read-only sections (such as ".text").
4206 This can be a significant performance improvement on some
4207 (notably embedded) targets.
4209 * New command "generate-core-file" (or "gcore").
4211 This new gdb command allows the user to drop a core file of the child
4212 process state at any time. So far it's been implemented only for
4213 GNU/Linux and Solaris, but should be relatively easily ported to other
4214 hosts. Argument is core file name (defaults to core.<pid>).
4216 * New command line option
4218 GDB now accepts --pid or -p followed by a process id.
4220 * Change in command line behavior -- corefiles vs. process ids.
4222 There is a subtle behavior in the way in which GDB handles
4223 command line arguments. The first non-flag argument is always
4224 a program to debug, but the second non-flag argument may either
4225 be a corefile or a process id. Previously, GDB would attempt to
4226 open the second argument as a corefile, and if that failed, would
4227 issue a superfluous error message and then attempt to attach it as
4228 a process. Now, if the second argument begins with a non-digit,
4229 it will be treated as a corefile. If it begins with a digit,
4230 GDB will attempt to attach it as a process, and if no such process
4231 is found, will then attempt to open it as a corefile.
4233 * Changes in ARM configurations.
4235 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4236 configuration is fully multi-arch.
4238 * New native configurations
4240 ARM NetBSD arm*-*-netbsd*
4241 x86 OpenBSD i[3456]86-*-openbsd*
4242 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4243 Sparc64 running FreeBSD sparc64-*-freebsd*
4247 Sanyo XStormy16 xstormy16-elf
4249 * OBSOLETE configurations and files
4251 Configurations that have been declared obsolete in this release have
4252 been commented out. Unless there is activity to revive these
4253 configurations, the next release of GDB will have their sources
4254 permanently REMOVED.
4256 AMD 29k family via UDI a29k-amd-udi, udi29k
4257 A29K VxWorks a29k-*-vxworks
4258 AMD 29000 embedded, using EBMON a29k-none-none
4259 AMD 29000 embedded with COFF a29k-none-coff
4260 AMD 29000 embedded with a.out a29k-none-aout
4262 testsuite/gdb.hp/gdb.threads-hp/ directory
4264 * REMOVED configurations and files
4266 TI TMS320C80 tic80-*-*
4268 PowerPC Solaris powerpcle-*-solaris*
4269 PowerPC Windows NT powerpcle-*-cygwin32
4270 PowerPC Netware powerpc-*-netware*
4271 Harris/CXUX m88k m88*-harris-cxux*
4272 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4273 ns32k-utek-sysv* ns32k-utek-*
4274 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4275 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4276 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4277 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4278 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4280 * Changes to command line processing
4282 The new `--args' feature can be used to specify command-line arguments
4283 for the inferior from gdb's command line.
4285 * Changes to key bindings
4287 There is a new `operate-and-get-next' function bound to `C-o'.
4289 *** Changes in GDB 5.1.1
4291 Fix compile problem on DJGPP.
4293 Fix a problem with floating-point registers on the i386 being
4296 Fix to stop GDB crashing on .debug_str debug info.
4298 Numerous documentation fixes.
4300 Numerous testsuite fixes.
4302 *** Changes in GDB 5.1:
4304 * New native configurations
4306 Alpha FreeBSD alpha*-*-freebsd*
4307 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4308 MIPS GNU/Linux mips*-*-linux*
4309 MIPS SGI Irix 6.x mips*-sgi-irix6*
4310 ia64 AIX ia64-*-aix*
4311 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4315 Motorola 68HC11 and 68HC12 m68hc11-elf
4317 UltraSparc running GNU/Linux sparc64-*-linux*
4319 * OBSOLETE configurations and files
4321 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4322 Harris/CXUX m88k m88*-harris-cxux*
4323 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4324 ns32k-utek-sysv* ns32k-utek-*
4325 TI TMS320C80 tic80-*-*
4327 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4328 PowerPC Solaris powerpcle-*-solaris*
4329 PowerPC Windows NT powerpcle-*-cygwin32
4330 PowerPC Netware powerpc-*-netware*
4331 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4332 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4333 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4334 Apple Macintosh (MPW) host N/A
4336 stuff.c (Program to stuff files into a specially prepared space in kdb)
4337 kdb-start.c (Main loop for the standalone kernel debugger)
4339 Configurations that have been declared obsolete in this release have
4340 been commented out. Unless there is activity to revive these
4341 configurations, the next release of GDB will have their sources
4342 permanently REMOVED.
4344 * REMOVED configurations and files
4346 Altos 3068 m68*-altos-*
4347 Convex c1-*-*, c2-*-*
4349 ARM RISCix arm-*-* (as host)
4353 * GDB has been converted to ISO C.
4355 GDB's source code has been converted to ISO C. In particular, the
4356 sources are fully protoized, and rely on standard headers being
4361 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4363 * The MI enabled by default.
4365 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4366 revised and enabled by default. Packages which use GDB as a debugging
4367 engine behind a UI or another front end are encouraged to switch to
4368 using the GDB/MI interface, instead of the old annotations interface
4369 which is now deprecated.
4371 * Support for debugging Pascal programs.
4373 GDB now includes support for debugging Pascal programs. The following
4374 main features are supported:
4376 - Pascal-specific data types such as sets;
4378 - automatic recognition of Pascal sources based on file-name
4381 - Pascal-style display of data types, variables, and functions;
4383 - a Pascal expression parser.
4385 However, some important features are not yet supported.
4387 - Pascal string operations are not supported at all;
4389 - there are some problems with boolean types;
4391 - Pascal type hexadecimal constants are not supported
4392 because they conflict with the internal variables format;
4394 - support for Pascal objects and classes is not full yet;
4396 - unlike Pascal, GDB is case-sensitive for symbol names.
4398 * Changes in completion.
4400 Commands such as `shell', `run' and `set args', which pass arguments
4401 to inferior programs, now complete on file names, similar to what
4402 users expect at the shell prompt.
4404 Commands which accept locations, such as `disassemble', `print',
4405 `breakpoint', `until', etc. now complete on filenames as well as
4406 program symbols. Thus, if you type "break foob TAB", and the source
4407 files linked into the programs include `foobar.c', that file name will
4408 be one of the candidates for completion. However, file names are not
4409 considered for completion after you typed a colon that delimits a file
4410 name from a name of a function in that file, as in "break foo.c:bar".
4412 `set demangle-style' completes on available demangling styles.
4414 * New platform-independent commands:
4416 It is now possible to define a post-hook for a command as well as a
4417 hook that runs before the command. For more details, see the
4418 documentation of `hookpost' in the GDB manual.
4420 * Changes in GNU/Linux native debugging.
4422 Support for debugging multi-threaded programs has been completely
4423 revised for all platforms except m68k and sparc. You can now debug as
4424 many threads as your system allows you to have.
4426 Attach/detach is supported for multi-threaded programs.
4428 Support for SSE registers was added for x86. This doesn't work for
4429 multi-threaded programs though.
4431 * Changes in MIPS configurations.
4433 Multi-arch support is enabled for all MIPS configurations.
4435 GDB can now be built as native debugger on SGI Irix 6.x systems for
4436 debugging n32 executables. (Debugging 64-bit executables is not yet
4439 * Unified support for hardware watchpoints in all x86 configurations.
4441 Most (if not all) native x86 configurations support hardware-assisted
4442 breakpoints and watchpoints in a unified manner. This support
4443 implements debug register sharing between watchpoints, which allows to
4444 put a virtually infinite number of watchpoints on the same address,
4445 and also supports watching regions up to 16 bytes with several debug
4448 The new maintenance command `maintenance show-debug-regs' toggles
4449 debugging print-outs in functions that insert, remove, and test
4450 watchpoints and hardware breakpoints.
4452 * Changes in the DJGPP native configuration.
4454 New command ``info dos sysinfo'' displays assorted information about
4455 the CPU, OS, memory, and DPMI server.
4457 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4458 display information about segment descriptors stored in GDT, LDT, and
4461 New commands ``info dos pde'' and ``info dos pte'' display entries
4462 from Page Directory and Page Tables (for now works with CWSDPMI only).
4463 New command ``info dos address-pte'' displays the Page Table entry for
4464 a given linear address.
4466 GDB can now pass command lines longer than 126 characters to the
4467 program being debugged (requires an update to the libdbg.a library
4468 which is part of the DJGPP development kit).
4470 DWARF2 debug info is now supported.
4472 It is now possible to `step' and `next' through calls to `longjmp'.
4474 * Changes in documentation.
4476 All GDB documentation was converted to GFDL, the GNU Free
4477 Documentation License.
4479 Tracepoints-related commands are now fully documented in the GDB
4482 TUI, the Text-mode User Interface, is now documented in the manual.
4484 Tracepoints-related commands are now fully documented in the GDB
4487 The "GDB Internals" manual now has an index. It also includes
4488 documentation of `ui_out' functions, GDB coding standards, x86
4489 hardware watchpoints, and memory region attributes.
4491 * GDB's version number moved to ``version.in''
4493 The Makefile variable VERSION has been replaced by the file
4494 ``version.in''. People creating GDB distributions should update the
4495 contents of this file.
4499 GUD support is now a standard part of the EMACS distribution.
4501 *** Changes in GDB 5.0:
4503 * Improved support for debugging FP programs on x86 targets
4505 Unified and much-improved support for debugging floating-point
4506 programs on all x86 targets. In particular, ``info float'' now
4507 displays the FP registers in the same format on all x86 targets, with
4508 greater level of detail.
4510 * Improvements and bugfixes in hardware-assisted watchpoints
4512 It is now possible to watch array elements, struct members, and
4513 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4514 on x86 targets no longer erroneously trigger when the address is
4517 * Improvements in the native DJGPP version of GDB
4519 The distribution now includes all the scripts and auxiliary files
4520 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4521 machines ``out of the box''.
4523 The DJGPP version can now debug programs that use signals. It is
4524 possible to catch signals that happened in the debuggee, deliver
4525 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4526 would kill the program being debugged.) Programs that hook hardware
4527 interrupts (keyboard, timer, etc.) can also be debugged.
4529 It is now possible to debug DJGPP programs that redirect their
4530 standard handles or switch them to raw (as opposed to cooked) mode, or
4531 even close them. The command ``run < foo > bar'' works as expected,
4532 and ``info terminal'' reports useful information about the debuggee's
4533 terminal, including raw/cooked mode, redirection, etc.
4535 The DJGPP version now uses termios functions for console I/O, which
4536 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4539 DOS-style file names with drive letters are now fully supported by
4542 It is now possible to debug DJGPP programs that switch their working
4543 directory. It is also possible to rerun the debuggee any number of
4544 times without restarting GDB; thus, you can use the same setup,
4545 breakpoints, etc. for many debugging sessions.
4547 * New native configurations
4549 ARM GNU/Linux arm*-*-linux*
4550 PowerPC GNU/Linux powerpc-*-linux*
4554 Motorola MCore mcore-*-*
4555 x86 VxWorks i[3456]86-*-vxworks*
4556 PowerPC VxWorks powerpc-*-vxworks*
4557 TI TMS320C80 tic80-*-*
4559 * OBSOLETE configurations
4561 Altos 3068 m68*-altos-*
4562 Convex c1-*-*, c2-*-*
4564 ARM RISCix arm-*-* (as host)
4567 Configurations that have been declared obsolete will be commented out,
4568 but the code will be left in place. If there is no activity to revive
4569 these configurations before the next release of GDB, the sources will
4570 be permanently REMOVED.
4572 * Gould support removed
4574 Support for the Gould PowerNode and NP1 has been removed.
4576 * New features for SVR4
4578 On SVR4 native platforms (such as Solaris), if you attach to a process
4579 without first loading a symbol file, GDB will now attempt to locate and
4580 load symbols from the running process's executable file.
4582 * Many C++ enhancements
4584 C++ support has been greatly improved. Overload resolution now works properly
4585 in almost all cases. RTTI support is on the way.
4587 * Remote targets can connect to a sub-program
4589 A popen(3) style serial-device has been added. This device starts a
4590 sub-process (such as a stand-alone simulator) and then communicates
4591 with that. The sub-program to run is specified using the syntax
4592 ``|<program> <args>'' vis:
4594 (gdb) set remotedebug 1
4595 (gdb) target extended-remote |mn10300-elf-sim program-args
4597 * MIPS 64 remote protocol
4599 A long standing bug in the mips64 remote protocol where by GDB
4600 expected certain 32 bit registers (ex SR) to be transfered as 32
4601 instead of 64 bits has been fixed.
4603 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4604 added to provide backward compatibility with older versions of GDB.
4606 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4608 The command ``set remotebinarydownload'' command has been replaced by
4609 ``set remote X-packet''. Other commands in ``set remote'' family
4610 include ``set remote P-packet''.
4612 * Breakpoint commands accept ranges.
4614 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4615 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4616 ``tracepoint passcount'' also accepts a range of tracepoints.
4618 * ``apropos'' command added.
4620 The ``apropos'' command searches through command names and
4621 documentation strings, printing out matches, making it much easier to
4622 try to find a command that does what you are looking for.
4626 A new machine oriented interface (MI) has been added to GDB. This
4627 interface is designed for debug environments running GDB as a separate
4628 process. This is part of the long term libGDB project. See the
4629 "GDB/MI" chapter of the GDB manual for further information. It can be
4630 enabled by configuring with:
4632 .../configure --enable-gdbmi
4634 *** Changes in GDB-4.18:
4636 * New native configurations
4638 HP-UX 10.20 hppa*-*-hpux10.20
4639 HP-UX 11.x hppa*-*-hpux11.0*
4640 M68K GNU/Linux m68*-*-linux*
4644 Fujitsu FR30 fr30-*-elf*
4645 Intel StrongARM strongarm-*-*
4646 Mitsubishi D30V d30v-*-*
4648 * OBSOLETE configurations
4650 Gould PowerNode, NP1 np1-*-*, pn-*-*
4652 Configurations that have been declared obsolete will be commented out,
4653 but the code will be left in place. If there is no activity to revive
4654 these configurations before the next release of GDB, the sources will
4655 be permanently REMOVED.
4659 As a compatibility experiment, GDB's source files buildsym.h and
4660 buildsym.c have been converted to pure standard C, no longer
4661 containing any K&R compatibility code. We believe that all systems in
4662 use today either come with a standard C compiler, or have a GCC port
4663 available. If this is not true, please report the affected
4664 configuration to bug-gdb@gnu.org immediately. See the README file for
4665 information about getting a standard C compiler if you don't have one
4670 GDB now uses readline 2.2.
4672 * set extension-language
4674 You can now control the mapping between filename extensions and source
4675 languages by using the `set extension-language' command. For instance,
4676 you can ask GDB to treat .c files as C++ by saying
4677 set extension-language .c c++
4678 The command `info extensions' lists all of the recognized extensions
4679 and their associated languages.
4681 * Setting processor type for PowerPC and RS/6000
4683 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4684 you can use the `set processor' command to specify what variant of the
4685 PowerPC family you are debugging. The command
4689 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4690 following PowerPC and RS6000 variants:
4692 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4693 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4695 403GC IBM PowerPC 403GC
4696 505 Motorola PowerPC 505
4697 860 Motorola PowerPC 860 or 850
4698 601 Motorola PowerPC 601
4699 602 Motorola PowerPC 602
4700 603 Motorola/IBM PowerPC 603 or 603e
4701 604 Motorola PowerPC 604 or 604e
4702 750 Motorola/IBM PowerPC 750 or 750
4704 At the moment, this command just tells GDB what to name the
4705 special-purpose processor registers. Since almost all the affected
4706 registers are inaccessible to user-level programs, this command is
4707 only useful for remote debugging in its present form.
4711 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4712 more extensive support for HP-UX. Added features include shared
4713 library support, kernel threads and hardware watchpoints for 11.00,
4714 support for HP's ANSI C and C++ compilers, and a compatibility mode
4715 for xdb and dbx commands.
4719 HP's donation includes the new concept of catchpoints, which is a
4720 generalization of the old catch command. On HP-UX, it is now possible
4721 to catch exec, fork, and vfork, as well as library loading.
4723 This means that the existing catch command has changed; its first
4724 argument now specifies the type of catch to be set up. See the
4725 output of "help catch" for a list of catchpoint types.
4727 * Debugging across forks
4729 On HP-UX, you can choose which process to debug when a fork() happens
4734 HP has donated a curses-based terminal user interface (TUI). To get
4735 it, build with --enable-tui. Although this can be enabled for any
4736 configuration, at present it only works for native HP debugging.
4738 * GDB remote protocol additions
4740 A new protocol packet 'X' that writes binary data is now available.
4741 Default behavior is to try 'X', then drop back to 'M' if the stub
4742 fails to respond. The settable variable `remotebinarydownload'
4743 allows explicit control over the use of 'X'.
4745 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4746 full 64-bit address. The command
4748 set remoteaddresssize 32
4750 can be used to revert to the old behaviour. For existing remote stubs
4751 the change should not be noticed, as the additional address information
4754 In order to assist in debugging stubs, you may use the maintenance
4755 command `packet' to send any text string to the stub. For instance,
4757 maint packet heythere
4759 sends the packet "$heythere#<checksum>". Note that it is very easy to
4760 disrupt a debugging session by sending the wrong packet at the wrong
4763 The compare-sections command allows you to compare section data on the
4764 target to what is in the executable file without uploading or
4765 downloading, by comparing CRC checksums.
4767 * Tracing can collect general expressions
4769 You may now collect general expressions at tracepoints. This requires
4770 further additions to the target-side stub; see tracepoint.c and
4771 doc/agentexpr.texi for further details.
4773 * mask-address variable for Mips
4775 For Mips targets, you may control the zeroing of the upper 32 bits of
4776 a 64-bit address by entering `set mask-address on'. This is mainly
4777 of interest to users of embedded R4xxx and R5xxx processors.
4779 * Higher serial baud rates
4781 GDB's serial code now allows you to specify baud rates 57600, 115200,
4782 230400, and 460800 baud. (Note that your host system may not be able
4783 to achieve all of these rates.)
4787 The i960 configuration now includes an initial implementation of a
4788 builtin simulator, contributed by Jim Wilson.
4791 *** Changes in GDB-4.17:
4793 * New native configurations
4795 Alpha GNU/Linux alpha*-*-linux*
4796 Unixware 2.x i[3456]86-unixware2*
4797 Irix 6.x mips*-sgi-irix6*
4798 PowerPC GNU/Linux powerpc-*-linux*
4799 PowerPC Solaris powerpcle-*-solaris*
4800 Sparc GNU/Linux sparc-*-linux*
4801 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4805 Argonaut Risc Chip (ARC) arc-*-*
4806 Hitachi H8/300S h8300*-*-*
4807 Matsushita MN10200 w/simulator mn10200-*-*
4808 Matsushita MN10300 w/simulator mn10300-*-*
4809 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4810 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4811 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4812 Mitsubishi D10V w/simulator d10v-*-*
4813 Mitsubishi M32R/D w/simulator m32r-*-elf*
4814 Tsqware Sparclet sparclet-*-*
4815 NEC V850 w/simulator v850-*-*
4817 * New debugging protocols
4819 ARM with RDI protocol arm*-*-*
4820 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4821 DDB and LSI variants of PMON protocol mips*-*-*
4822 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4823 PowerPC with SDS protocol powerpc{,le}-*-eabi
4824 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4828 All configurations can now understand and use the DWARF 2 debugging
4829 format. The choice is automatic, if the symbol file contains DWARF 2
4834 GDB now includes basic Java language support. This support is
4835 only useful with Java compilers that produce native machine code.
4837 * solib-absolute-prefix and solib-search-path
4839 For SunOS and SVR4 shared libraries, you may now set the prefix for
4840 loading absolute shared library symbol files, and the search path for
4841 locating non-absolute shared library symbol files.
4843 * Live range splitting
4845 GDB can now effectively debug code for which GCC has performed live
4846 range splitting as part of its optimization. See gdb/doc/LRS for
4847 more details on the expected format of the stabs information.
4851 GDB's support for the GNU Hurd, including thread debugging, has been
4852 updated to work with current versions of the Hurd.
4856 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4857 instruction set. ARM GDB automatically detects when Thumb
4858 instructions are in use, and adjusts disassembly and backtracing
4863 GDB's MIPS target configurations now handle the MIP16 16-bit
4868 GDB now includes support for overlays; if an executable has been
4869 linked such that multiple sections are based at the same address, GDB
4870 will decide which section to use for symbolic info. You can choose to
4871 control the decision manually, using overlay commands, or implement
4872 additional target-side support and use "overlay load-target" to bring
4873 in the overlay mapping. Do "help overlay" for more detail.
4877 The command "info symbol <address>" displays information about
4878 the symbol at the specified address.
4882 The standard remote protocol now includes an extension that allows
4883 asynchronous collection and display of trace data. This requires
4884 extensive support in the target-side debugging stub. Tracing mode
4885 includes a new interaction mode in GDB and new commands: see the
4886 file tracepoint.c for more details.
4890 Configurations for embedded MIPS now include a simulator contributed
4891 by Cygnus Solutions. The simulator supports the instruction sets
4892 of most MIPS variants.
4896 Sparc configurations may now include the ERC32 simulator contributed
4897 by the European Space Agency. The simulator is not built into
4898 Sparc targets by default; configure with --enable-sim to include it.
4902 For target configurations that may include multiple variants of a
4903 basic architecture (such as MIPS and SH), you may now set the
4904 architecture explicitly. "set arch" sets, "info arch" lists
4905 the possible architectures.
4907 *** Changes in GDB-4.16:
4909 * New native configurations
4911 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4912 M68K NetBSD m68k-*-netbsd*
4913 PowerPC AIX 4.x powerpc-*-aix*
4914 PowerPC MacOS powerpc-*-macos*
4915 PowerPC Windows NT powerpcle-*-cygwin32
4916 RS/6000 AIX 4.x rs6000-*-aix4*
4920 ARM with RDP protocol arm-*-*
4921 I960 with MON960 i960-*-coff
4922 MIPS VxWorks mips*-*-vxworks*
4923 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4924 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4926 Matra Sparclet sparclet-*-*
4930 The powerpc-eabi configuration now includes the PSIM simulator,
4931 contributed by Andrew Cagney, with assistance from Mike Meissner.
4932 PSIM is a very elaborate model of the PowerPC, including not only
4933 basic instruction set execution, but also details of execution unit
4934 performance and I/O hardware. See sim/ppc/README for more details.
4938 GDB now works with Solaris 2.5.
4940 * Windows 95/NT native
4942 GDB will now work as a native debugger on Windows 95 and Windows NT.
4943 To build it from source, you must use the "gnu-win32" environment,
4944 which uses a DLL to emulate enough of Unix to run the GNU tools.
4945 Further information, binaries, and sources are available at
4946 ftp.cygnus.com, under pub/gnu-win32.
4948 * dont-repeat command
4950 If a user-defined command includes the command `dont-repeat', then the
4951 command will not be repeated if the user just types return. This is
4952 useful if the command is time-consuming to run, so that accidental
4953 extra keystrokes don't run the same command many times.
4955 * Send break instead of ^C
4957 The standard remote protocol now includes an option to send a break
4958 rather than a ^C to the target in order to interrupt it. By default,
4959 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4961 * Remote protocol timeout
4963 The standard remote protocol includes a new variable `remotetimeout'
4964 that allows you to set the number of seconds before GDB gives up trying
4965 to read from the target. The default value is 2.
4967 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4969 By default GDB will automatically keep track of objects as they are
4970 loaded and unloaded by the dynamic linker. By using the command `set
4971 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4972 when shared library events occur, thus allowing you to set breakpoints
4973 in shared libraries which are explicitly loaded by the inferior.
4975 Note this feature does not work on hpux8. On hpux9 you must link
4976 /usr/lib/end.o into your program. This feature should work
4977 automatically on hpux10.
4979 * Irix 5.x hardware watchpoint support
4981 Irix 5 configurations now support the use of hardware watchpoints.
4983 * Mips protocol "SYN garbage limit"
4985 When debugging a Mips target using the `target mips' protocol, you
4986 may set the number of characters that GDB will ignore by setting
4987 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4988 every character. The default value is 1050.
4990 * Recording and replaying remote debug sessions
4992 If you set `remotelogfile' to the name of a file, gdb will write to it
4993 a recording of a remote debug session. This recording may then be
4994 replayed back to gdb using "gdbreplay". See gdbserver/README for
4995 details. This is useful when you have a problem with GDB while doing
4996 remote debugging; you can make a recording of the session and send it
4997 to someone else, who can then recreate the problem.
4999 * Speedups for remote debugging
5001 GDB includes speedups for downloading and stepping MIPS systems using
5002 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5003 and more efficient S-record downloading.
5005 * Memory use reductions and statistics collection
5007 GDB now uses less memory and reports statistics about memory usage.
5008 Try the `maint print statistics' command, for example.
5010 *** Changes in GDB-4.15:
5012 * Psymtabs for XCOFF
5014 The symbol reader for AIX GDB now uses partial symbol tables. This
5015 can greatly improve startup time, especially for large executables.
5017 * Remote targets use caching
5019 Remote targets now use a data cache to speed up communication with the
5020 remote side. The data cache could lead to incorrect results because
5021 it doesn't know about volatile variables, thus making it impossible to
5022 debug targets which use memory mapped I/O devices. `set remotecache
5023 off' turns the the data cache off.
5025 * Remote targets may have threads
5027 The standard remote protocol now includes support for multiple threads
5028 in the target system, using new protocol commands 'H' and 'T'. See
5029 gdb/remote.c for details.
5033 If GDB is configured with `--enable-netrom', then it will include
5034 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5035 acts as though it is a bank of ROM on the target board, but you can
5036 write into it over the network. GDB's support consists only of
5037 support for fast loading into the emulated ROM; to debug, you must use
5038 another protocol, such as standard remote protocol. The usual
5039 sequence is something like
5041 target nrom <netrom-hostname>
5043 target remote <netrom-hostname>:1235
5047 GDB now includes support for the Apple Macintosh, as a host only. It
5048 may be run as either an MPW tool or as a standalone application, and
5049 it can debug through the serial port. All the usual GDB commands are
5050 available, but to the target command, you must supply "serial" as the
5051 device type instead of "/dev/ttyXX". See mpw-README in the main
5052 directory for more information on how to build. The MPW configuration
5053 scripts */mpw-config.in support only a few targets, and only the
5054 mips-idt-ecoff target has been tested.
5058 GDB configuration now uses autoconf. This is not user-visible,
5059 but does simplify configuration and building.
5063 GDB now supports hpux10.
5065 *** Changes in GDB-4.14:
5067 * New native configurations
5069 x86 FreeBSD i[345]86-*-freebsd
5070 x86 NetBSD i[345]86-*-netbsd
5071 NS32k NetBSD ns32k-*-netbsd
5072 Sparc NetBSD sparc-*-netbsd
5076 A29K VxWorks a29k-*-vxworks
5077 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5078 CPU32 EST-300 emulator m68*-*-est*
5079 PowerPC ELF powerpc-*-elf
5082 * Alpha OSF/1 support for procfs
5084 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5085 possible to attach to running processes. As the mounting of the /proc
5086 filesystem is optional on the Alpha, GDB automatically determines
5087 the availability of /proc during startup. This can lead to problems
5088 if /proc is unmounted after GDB has been started.
5090 * Arguments to user-defined commands
5092 User commands may accept up to 10 arguments separated by whitespace.
5093 Arguments are accessed within the user command via $arg0..$arg9. A
5096 print $arg0 + $arg1 + $arg2
5098 To execute the command use:
5101 Defines the command "adder" which prints the sum of its three arguments.
5102 Note the arguments are text substitutions, so they may reference variables,
5103 use complex expressions, or even perform inferior function calls.
5105 * New `if' and `while' commands
5107 This makes it possible to write more sophisticated user-defined
5108 commands. Both commands take a single argument, which is the
5109 expression to evaluate, and must be followed by the commands to
5110 execute, one per line, if the expression is nonzero, the list being
5111 terminated by the word `end'. The `if' command list may include an
5112 `else' word, which causes the following commands to be executed only
5113 if the expression is zero.
5115 * Fortran source language mode
5117 GDB now includes partial support for Fortran 77. It will recognize
5118 Fortran programs and can evaluate a subset of Fortran expressions, but
5119 variables and functions may not be handled correctly. GDB will work
5120 with G77, but does not yet know much about symbols emitted by other
5123 * Better HPUX support
5125 Most debugging facilities now work on dynamic executables for HPPAs
5126 running hpux9 or later. You can attach to running dynamically linked
5127 processes, but by default the dynamic libraries will be read-only, so
5128 for instance you won't be able to put breakpoints in them. To change
5129 that behavior do the following before running the program:
5135 This will cause the libraries to be mapped private and read-write.
5136 To revert to the normal behavior, do this:
5142 You cannot set breakpoints or examine data in the library until after
5143 the library is loaded if the function/data symbols do not have
5146 GDB can now also read debug symbols produced by the HP C compiler on
5147 HPPAs (sorry, no C++, Fortran or 68k support).
5149 * Target byte order now dynamically selectable
5151 You can choose which byte order to use with a target system, via the
5152 commands "set endian big" and "set endian little", and you can see the
5153 current setting by using "show endian". You can also give the command
5154 "set endian auto", in which case GDB will use the byte order
5155 associated with the executable. Currently, only embedded MIPS
5156 configurations support dynamic selection of target byte order.
5158 * New DOS host serial code
5160 This version uses DPMI interrupts to handle buffered I/O, so you
5161 no longer need to run asynctsr when debugging boards connected to
5164 *** Changes in GDB-4.13:
5166 * New "complete" command
5168 This lists all the possible completions for the rest of the line, if it
5169 were to be given as a command itself. This is intended for use by emacs.
5171 * Trailing space optional in prompt
5173 "set prompt" no longer adds a space for you after the prompt you set. This
5174 allows you to set a prompt which ends in a space or one that does not.
5176 * Breakpoint hit counts
5178 "info break" now displays a count of the number of times the breakpoint
5179 has been hit. This is especially useful in conjunction with "ignore"; you
5180 can ignore a large number of breakpoint hits, look at the breakpoint info
5181 to see how many times the breakpoint was hit, then run again, ignoring one
5182 less than that number, and this will get you quickly to the last hit of
5185 * Ability to stop printing at NULL character
5187 "set print null-stop" will cause GDB to stop printing the characters of
5188 an array when the first NULL is encountered. This is useful when large
5189 arrays actually contain only short strings.
5191 * Shared library breakpoints
5193 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5194 breakpoints in shared libraries before the executable is run.
5196 * Hardware watchpoints
5198 There is a new hardware breakpoint for the watch command for sparclite
5199 targets. See gdb/sparclite/hw_breakpoint.note.
5201 Hardware watchpoints are also now supported under GNU/Linux.
5205 Annotations have been added. These are for use with graphical interfaces,
5206 and are still experimental. Currently only gdba.el uses these.
5208 * Improved Irix 5 support
5210 GDB now works properly with Irix 5.2.
5212 * Improved HPPA support
5214 GDB now works properly with the latest GCC and GAS.
5216 * New native configurations
5218 Sequent PTX4 i[34]86-sequent-ptx4
5219 HPPA running OSF/1 hppa*-*-osf*
5220 Atari TT running SVR4 m68*-*-sysv4*
5221 RS/6000 LynxOS rs6000-*-lynxos*
5225 OS/9000 i[34]86-*-os9k
5226 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5229 * Hitachi SH7000 and E7000-PC ICE support
5231 There is now support for communicating with the Hitachi E7000-PC ICE.
5232 This is available automatically when GDB is configured for the SH.
5236 As usual, a variety of small fixes and improvements, both generic
5237 and configuration-specific. See the ChangeLog for more detail.
5239 *** Changes in GDB-4.12:
5241 * Irix 5 is now supported
5245 GDB-4.12 on the HPPA has a number of changes which make it unable
5246 to debug the output from the currently released versions of GCC and
5247 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5248 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5249 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5252 *** Changes in GDB-4.11:
5254 * User visible changes:
5258 The "set remotedebug" option is now consistent between the mips remote
5259 target, remote targets using the gdb-specific protocol, UDI (AMD's
5260 debug protocol for the 29k) and the 88k bug monitor. It is now an
5261 integer specifying a debug level (normally 0 or 1, but 2 means more
5262 debugging info for the mips target).
5264 * DEC Alpha native support
5266 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5267 debug info, but GDB works fairly well with the DEC compiler and should
5268 work with a future GCC release. See the README file for a few
5269 Alpha-specific notes.
5271 * Preliminary thread implementation
5273 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5275 * LynxOS native and target support for 386
5277 This release has been hosted on LynxOS 2.2, and also can be configured
5278 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5281 * Improvements in C++ mangling/demangling.
5283 This release has much better g++ debugging, specifically in name
5284 mangling/demangling, virtual function calls, print virtual table,
5285 call methods, ...etc.
5287 *** Changes in GDB-4.10:
5289 * User visible changes:
5291 Remote debugging using the GDB-specific (`target remote') protocol now
5292 supports the `load' command. This is only useful if you have some
5293 other way of getting the stub to the target system, and you can put it
5294 somewhere in memory where it won't get clobbered by the download.
5296 Filename completion now works.
5298 When run under emacs mode, the "info line" command now causes the
5299 arrow to point to the line specified. Also, "info line" prints
5300 addresses in symbolic form (as well as hex).
5302 All vxworks based targets now support a user settable option, called
5303 vxworks-timeout. This option represents the number of seconds gdb
5304 should wait for responses to rpc's. You might want to use this if
5305 your vxworks target is, perhaps, a slow software simulator or happens
5306 to be on the far side of a thin network line.
5310 This release contains support for using a DEC alpha as a GDB host for
5311 cross debugging. Native alpha debugging is not supported yet.
5314 *** Changes in GDB-4.9:
5318 This is the first GDB release which is accompanied by a matching testsuite.
5319 The testsuite requires installation of dejagnu, which should be available
5320 via ftp from most sites that carry GNU software.
5324 'Cfront' style demangling has had its name changed to 'ARM' style, to
5325 emphasize that it was written from the specifications in the C++ Annotated
5326 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5327 disclaimers, it still generated too much confusion with users attempting to
5328 use gdb with AT&T cfront.
5332 GDB now uses a standard remote interface to a simulator library.
5333 So far, the library contains simulators for the Zilog Z8001/2, the
5334 Hitachi H8/300, H8/500 and Super-H.
5336 * New targets supported
5338 H8/300 simulator h8300-hitachi-hms or h8300hms
5339 H8/500 simulator h8500-hitachi-hms or h8500hms
5340 SH simulator sh-hitachi-hms or sh
5341 Z8000 simulator z8k-zilog-none or z8ksim
5342 IDT MIPS board over serial line mips-idt-ecoff
5344 Cross-debugging to GO32 targets is supported. It requires a custom
5345 version of the i386-stub.c module which is integrated with the
5346 GO32 memory extender.
5348 * New remote protocols
5350 MIPS remote debugging protocol.
5352 * New source languages supported
5354 This version includes preliminary support for Chill, a Pascal like language
5355 used by telecommunications companies. Chill support is also being integrated
5356 into the GNU compiler, but we don't know when it will be publically available.
5359 *** Changes in GDB-4.8:
5361 * HP Precision Architecture supported
5363 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5364 version of this support was available as a set of patches from the
5365 University of Utah. GDB does not support debugging of programs
5366 compiled with the HP compiler, because HP will not document their file
5367 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5368 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5370 Many problems in the preliminary version have been fixed.
5372 * Faster and better demangling
5374 We have improved template demangling and fixed numerous bugs in the GNU style
5375 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5376 character types (wchar_t) are now supported. Demangling of each symbol is now
5377 only done once, and is cached when the symbol table for a file is read in.
5378 This results in a small increase in memory usage for C programs, a moderate
5379 increase in memory usage for C++ programs, and a fantastic speedup in
5382 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5383 from the specifications in the Annotated Reference Manual, which AT&T's
5384 compiler does not actually implement.
5386 * G++ multiple inheritance compiler problem
5388 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5389 inheritance lattices was reworked to properly discover ambiguities. We
5390 recently found an example which causes this new algorithm to fail in a
5391 very subtle way, producing bad debug information for those classes.
5392 The file 'gcc.patch' (in this directory) can be applied to gcc to
5393 circumvent the problem. A future GCC release will contain a complete
5396 The previous G++ debug info problem (mentioned below for the gdb-4.7
5397 release) is fixed in gcc version 2.3.2.
5399 * Improved configure script
5401 The `configure' script will now attempt to guess your system type if
5402 you don't supply a host system type. The old scheme of supplying a
5403 host system triplet is preferable over using this. All the magic is
5404 done in the new `config.guess' script. Examine it for details.
5406 We have also brought our configure script much more in line with the FSF's
5407 version. It now supports the --with-xxx options. In particular,
5408 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5409 The resulting GDB will not be able to read arbitrary object file formats --
5410 only the format ``expected'' to be used on the configured target system.
5411 We hope to make this the default in a future release.
5413 * Documentation improvements
5415 There's new internal documentation on how to modify GDB, and how to
5416 produce clean changes to the code. We implore people to read it
5417 before submitting changes.
5419 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5420 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5421 `info' files are also provided. To build `info' files from scratch,
5422 you will need the latest `makeinfo' release, which will be available in
5423 a future texinfo-X.Y release.
5425 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5426 We're not sure exactly which versions have this problem, but it has
5427 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5428 or better. If that isn't possible, there is a patch in
5429 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5430 around this problem.
5434 GDB now supports array constants that can be used in expressions typed in by
5435 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5436 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5439 The new directory `gdb/sparclite' contains a program that demonstrates
5440 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5442 * New native hosts supported
5444 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5445 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5447 * New targets supported
5449 AMD 29k family via UDI a29k-amd-udi or udi29k
5451 * New file formats supported
5453 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5454 HPUX core files, and SCO 3.2v2 core files.
5458 Attaching to processes now works again; thanks for the many bug reports.
5460 We have also stomped on a bunch of core dumps caused by
5461 printf_filtered("%s") problems.
5463 We eliminated a copyright problem on the rpc and ptrace header files
5464 for VxWorks, which was discovered at the last minute during the 4.7
5465 release. You should now be able to build a VxWorks GDB.
5467 You can now interrupt gdb while an attached process is running. This
5468 will cause the attached process to stop, and give control back to GDB.
5470 We fixed problems caused by using too many file descriptors
5471 for reading symbols from object files and libraries. This was
5472 especially a problem for programs that used many (~100) shared
5475 The `step' command now only enters a subroutine if there is line number
5476 information for the subroutine. Otherwise it acts like the `next'
5477 command. Previously, `step' would enter subroutines if there was
5478 any debugging information about the routine. This avoids problems
5479 when using `cc -g1' on MIPS machines.
5481 * Internal improvements
5483 GDB's internal interfaces have been improved to make it easier to support
5484 debugging of multiple languages in the future.
5486 GDB now uses a common structure for symbol information internally.
5487 Minimal symbols (derived from linkage symbols in object files), partial
5488 symbols (from a quick scan of debug information), and full symbols
5489 contain a common subset of information, making it easier to write
5490 shared code that handles any of them.
5492 * New command line options
5494 We now accept --silent as an alias for --quiet.
5498 The memory-mapped-malloc library is now licensed under the GNU Library
5499 General Public License.
5501 *** Changes in GDB-4.7:
5503 * Host/native/target split
5505 GDB has had some major internal surgery to untangle the support for
5506 hosts and remote targets. Now, when you configure GDB for a remote
5507 target, it will no longer load in all of the support for debugging
5508 local programs on the host. When fully completed and tested, this will
5509 ensure that arbitrary host/target combinations are possible.
5511 The primary conceptual shift is to separate the non-portable code in
5512 GDB into three categories. Host specific code is required any time GDB
5513 is compiled on that host, regardless of the target. Target specific
5514 code relates to the peculiarities of the target, but can be compiled on
5515 any host. Native specific code is everything else: it can only be
5516 built when the host and target are the same system. Child process
5517 handling and core file support are two common `native' examples.
5519 GDB's use of /proc for controlling Unix child processes is now cleaner.
5520 It has been split out into a single module under the `target_ops' vector,
5521 plus two native-dependent functions for each system that uses /proc.
5523 * New hosts supported
5525 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5526 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5527 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5529 * New targets supported
5531 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5532 68030 and CPU32 m68030-*-*, m68332-*-*
5534 * New native hosts supported
5536 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5537 (386bsd is not well tested yet)
5538 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5540 * New file formats supported
5542 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5543 supports reading of `a.out.adobe' object files, which are an a.out
5544 format extended with minimal information about multiple sections.
5548 `show copying' is the same as the old `info copying'.
5549 `show warranty' is the same as `info warrantee'.
5550 These were renamed for consistency. The old commands continue to work.
5552 `info handle' is a new alias for `info signals'.
5554 You can now define pre-command hooks, which attach arbitrary command
5555 scripts to any command. The commands in the hook will be executed
5556 prior to the user's command. You can also create a hook which will be
5557 executed whenever the program stops. See gdb.texinfo.
5561 We now deal with Cfront style name mangling, and can even extract type
5562 info from mangled symbols. GDB can automatically figure out which
5563 symbol mangling style your C++ compiler uses.
5565 Calling of methods and virtual functions has been improved as well.
5569 The crash that occured when debugging Sun Ansi-C compiled binaries is
5570 fixed. This was due to mishandling of the extra N_SO stabs output
5573 We also finally got Ultrix 4.2 running in house, and fixed core file
5574 support, with help from a dozen people on the net.
5576 John M. Farrell discovered that the reason that single-stepping was so
5577 slow on all of the Mips based platforms (primarily SGI and DEC) was
5578 that we were trying to demangle and lookup a symbol used for internal
5579 purposes on every instruction that was being stepped through. Changing
5580 the name of that symbol so that it couldn't be mistaken for a C++
5581 mangled symbol sped things up a great deal.
5583 Rich Pixley sped up symbol lookups in general by getting much smarter
5584 about when C++ symbol mangling is necessary. This should make symbol
5585 completion (TAB on the command line) much faster. It's not as fast as
5586 we'd like, but it's significantly faster than gdb-4.6.
5590 A new user controllable variable 'call_scratch_address' can
5591 specify the location of a scratch area to be used when GDB
5592 calls a function in the target. This is necessary because the
5593 usual method of putting the scratch area on the stack does not work
5594 in systems that have separate instruction and data spaces.
5596 We integrated changes to support the 29k UDI (Universal Debugger
5597 Interface), but discovered at the last minute that we didn't have all
5598 of the appropriate copyright paperwork. We are working with AMD to
5599 resolve this, and hope to have it available soon.
5603 We have sped up the remote serial line protocol, especially for targets
5604 with lots of registers. It now supports a new `expedited status' ('T')
5605 message which can be used in place of the existing 'S' status message.
5606 This allows the remote stub to send only the registers that GDB
5607 needs to make a quick decision about single-stepping or conditional
5608 breakpoints, eliminating the need to fetch the entire register set for
5609 each instruction being stepped through.
5611 The GDB remote serial protocol now implements a write-through cache for
5612 registers, only re-reading the registers if the target has run.
5614 There is also a new remote serial stub for SPARC processors. You can
5615 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5616 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5617 processor with a serial port.
5621 Configure.in files have become much easier to read and modify. A new
5622 `table driven' format makes it more obvious what configurations are
5623 supported, and what files each one uses.
5627 There is a new opcodes library which will eventually contain all of the
5628 disassembly routines and opcode tables. At present, it only contains
5629 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5630 disassembler (binutils/objdump) to share these routines.
5632 The libiberty library is now copylefted under the GNU Library General
5633 Public License. This allows more liberal use, and was done so libg++
5634 can use it. This makes no difference to GDB, since the Library License
5635 grants all the rights from the General Public License.
5639 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5640 reference to the stabs symbol info used by the debugger. It is (as far
5641 as we know) the only published document on this fascinating topic. We
5642 encourage you to read it, compare it to the stabs information on your
5643 system, and send improvements on the document in general (to
5644 bug-gdb@prep.ai.mit.edu).
5646 And, of course, many bugs have been fixed.
5649 *** Changes in GDB-4.6:
5651 * Better support for C++ function names
5653 GDB now accepts as input the "demangled form" of C++ overloaded function
5654 names and member function names, and can do command completion on such names
5655 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5656 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5657 Make use of command completion, it is your friend.
5659 GDB also now accepts a variety of C++ mangled symbol formats. They are
5660 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5661 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5662 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5663 for the list of formats.
5665 * G++ symbol mangling problem
5667 Recent versions of gcc have a bug in how they emit debugging information for
5668 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5669 directory) can be applied to gcc to fix the problem. Alternatively, if you
5670 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5671 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5672 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5675 * New 'maintenance' command
5677 All of the commands related to hacking GDB internals have been moved out of
5678 the main command set, and now live behind the 'maintenance' command. This
5679 can also be abbreviated as 'mt'. The following changes were made:
5681 dump-me -> maintenance dump-me
5682 info all-breakpoints -> maintenance info breakpoints
5683 printmsyms -> maintenance print msyms
5684 printobjfiles -> maintenance print objfiles
5685 printpsyms -> maintenance print psymbols
5686 printsyms -> maintenance print symbols
5688 The following commands are new:
5690 maintenance demangle Call internal GDB demangler routine to
5691 demangle a C++ link name and prints the result.
5692 maintenance print type Print a type chain for a given symbol
5694 * Change to .gdbinit file processing
5696 We now read the $HOME/.gdbinit file before processing the argv arguments
5697 (e.g. reading symbol files or core files). This allows global parameters to
5698 be set, which will apply during the symbol reading. The ./.gdbinit is still
5699 read after argv processing.
5701 * New hosts supported
5703 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5705 GNU/Linux support i386-unknown-linux or linux
5707 We are also including code to support the HP/PA running BSD and HPUX. This
5708 is almost guaranteed not to work, as we didn't have time to test or build it
5709 for this release. We are including it so that the more adventurous (or
5710 masochistic) of you can play with it. We also had major problems with the
5711 fact that the compiler that we got from HP doesn't support the -g option.
5714 * New targets supported
5716 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5718 * More smarts about finding #include files
5720 GDB now remembers the compilation directory for all include files, and for
5721 all files from which C is generated (like yacc and lex sources). This
5722 greatly improves GDB's ability to find yacc/lex sources, and include files,
5723 especially if you are debugging your program from a directory different from
5724 the one that contains your sources.
5726 We also fixed a bug which caused difficulty with listing and setting
5727 breakpoints in include files which contain C code. (In the past, you had to
5728 try twice in order to list an include file that you hadn't looked at before.)
5730 * Interesting infernals change
5732 GDB now deals with arbitrary numbers of sections, where the symbols for each
5733 section must be relocated relative to that section's landing place in the
5734 target's address space. This work was needed to support ELF with embedded
5735 stabs used by Solaris-2.0.
5737 * Bug fixes (of course!)
5739 There have been loads of fixes for the following things:
5740 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5741 i960, stabs, DOS(GO32), procfs, etc...
5743 See the ChangeLog for details.
5745 *** Changes in GDB-4.5:
5747 * New machines supported (host and target)
5749 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5751 SGI Irix-4.x mips-sgi-irix4 or iris4
5753 * New malloc package
5755 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5756 Mmalloc is capable of handling mutiple heaps of memory. It is also
5757 capable of saving a heap to a file, and then mapping it back in later.
5758 This can be used to greatly speedup the startup of GDB by using a
5759 pre-parsed symbol table which lives in a mmalloc managed heap. For
5760 more details, please read mmalloc/mmalloc.texi.
5764 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5765 'help info proc' for details.
5767 * MIPS ecoff symbol table format
5769 The code that reads MIPS symbol table format is now supported on all hosts.
5770 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5773 * File name changes for MS-DOS
5775 Many files in the config directories have been renamed to make it easier to
5776 support GDB on MS-DOSe systems (which have very restrictive file name
5777 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5778 environment) is close to working but has some remaining problems. Note
5779 that debugging of DOS programs is not supported, due to limitations
5780 in the ``operating system'', but it can be used to host cross-debugging.
5782 * Cross byte order fixes
5784 Many fixes have been made to support cross debugging of Sparc and MIPS
5785 targets from hosts whose byte order differs.
5787 * New -mapped and -readnow options
5789 If memory-mapped files are available on your system through the 'mmap'
5790 system call, you can use the -mapped option on the `file' or
5791 `symbol-file' commands to cause GDB to write the symbols from your
5792 program into a reusable file. If the program you are debugging is
5793 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5794 Future GDB debugging sessions will notice the presence of this file,
5795 and will quickly map in symbol information from it, rather than reading
5796 the symbol table from the executable program. Using the '-mapped'
5797 option in a GDB `file' or `symbol-file' command has the same effect as
5798 starting GDB with the '-mapped' command-line option.
5800 You can cause GDB to read the entire symbol table immediately by using
5801 the '-readnow' option with any of the commands that load symbol table
5802 information (or on the GDB command line). This makes the command
5803 slower, but makes future operations faster.
5805 The -mapped and -readnow options are typically combined in order to
5806 build a `fred.syms' file that contains complete symbol information.
5807 A simple GDB invocation to do nothing but build a `.syms' file for future
5810 gdb -batch -nx -mapped -readnow programname
5812 The `.syms' file is specific to the host machine on which GDB is run.
5813 It holds an exact image of GDB's internal symbol table. It cannot be
5814 shared across multiple host platforms.
5816 * longjmp() handling
5818 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5819 siglongjmp() without losing control. This feature has not yet been ported to
5820 all systems. It currently works on many 386 platforms, all MIPS-based
5821 platforms (SGI, DECstation, etc), and Sun3/4.
5825 Preliminary work has been put in to support the new Solaris OS from Sun. At
5826 this time, it can control and debug processes, but it is not capable of
5831 As always, many many bug fixes. The major areas were with g++, and mipsread.
5832 People using the MIPS-based platforms should experience fewer mysterious
5833 crashes and trashed symbol tables.
5835 *** Changes in GDB-4.4:
5837 * New machines supported (host and target)
5839 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5841 BSD Reno on Vax vax-dec-bsd
5842 Ultrix on Vax vax-dec-ultrix
5844 * New machines supported (target)
5846 AMD 29000 embedded, using EBMON a29k-none-none
5850 GDB continues to improve its handling of C++. `References' work better.
5851 The demangler has also been improved, and now deals with symbols mangled as
5852 per the Annotated C++ Reference Guide.
5854 GDB also now handles `stabs' symbol information embedded in MIPS
5855 `ecoff' symbol tables. Since the ecoff format was not easily
5856 extensible to handle new languages such as C++, this appeared to be a
5857 good way to put C++ debugging info into MIPS binaries. This option
5858 will be supported in the GNU C compiler, version 2, when it is
5861 * New features for SVR4
5863 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5864 shared libraries. Debugging dynamically linked programs should present
5865 only minor differences from debugging statically linked programs.
5867 The `info proc' command will print out information about any process
5868 on an SVR4 system (including the one you are debugging). At the moment,
5869 it prints the address mappings of the process.
5871 If you bring up GDB on another SVR4 system, please send mail to
5872 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5874 * Better dynamic linking support in SunOS
5876 Reading symbols from shared libraries which contain debugging symbols
5877 now works properly. However, there remain issues such as automatic
5878 skipping of `transfer vector' code during function calls, which
5879 make it harder to debug code in a shared library, than to debug the
5880 same code linked statically.
5884 GDB is now using the latest `getopt' routines from the FSF. This
5885 version accepts the -- prefix for options with long names. GDB will
5886 continue to accept the old forms (-option and +option) as well.
5887 Various single letter abbreviations for options have been explicity
5888 added to the option table so that they won't get overshadowed in the
5889 future by other options that begin with the same letter.
5893 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5894 Many assorted bugs have been handled. Many more remain to be handled.
5895 See the various ChangeLog files (primarily in gdb and bfd) for details.
5898 *** Changes in GDB-4.3:
5900 * New machines supported (host and target)
5902 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5903 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5904 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5906 * Almost SCO Unix support
5908 We had hoped to support:
5909 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5910 (except for core file support), but we discovered very late in the release
5911 that it has problems with process groups that render gdb unusable. Sorry
5912 about that. I encourage people to fix it and post the fixes.
5914 * Preliminary ELF and DWARF support
5916 GDB can read ELF object files on System V Release 4, and can handle
5917 debugging records for C, in DWARF format, in ELF files. This support
5918 is preliminary. If you bring up GDB on another SVR4 system, please
5919 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5924 GDB now uses the latest `readline' library. One user-visible change
5925 is that two tabs will list possible command completions, which previously
5926 required typing M-? (meta-question mark, or ESC ?).
5930 The `stepi' bug that many of you noticed has been squashed.
5931 Many bugs in C++ have been handled. Many more remain to be handled.
5932 See the various ChangeLog files (primarily in gdb and bfd) for details.
5934 * State of the MIPS world (in case you wondered):
5936 GDB can understand the symbol tables emitted by the compilers
5937 supplied by most vendors of MIPS-based machines, including DEC. These
5938 symbol tables are in a format that essentially nobody else uses.
5940 Some versions of gcc come with an assembler post-processor called
5941 mips-tfile. This program is required if you want to do source-level
5942 debugging of gcc-compiled programs. I believe FSF does not ship
5943 mips-tfile with gcc version 1, but it will eventually come with gcc
5946 Debugging of g++ output remains a problem. g++ version 1.xx does not
5947 really support it at all. (If you're lucky, you should be able to get
5948 line numbers and stack traces to work, but no parameters or local
5949 variables.) With some work it should be possible to improve the
5952 When gcc version 2 is released, you will have somewhat better luck.
5953 However, even then you will get confusing results for inheritance and
5956 We will eventually provide full debugging of g++ output on
5957 DECstations. This will probably involve some kind of stabs-in-ecoff
5958 encapulation, but the details have not been worked out yet.
5961 *** Changes in GDB-4.2:
5963 * Improved configuration
5965 Only one copy of `configure' exists now, and it is not self-modifying.
5966 Porting BFD is simpler.
5970 The `step' and `next' commands now only stop at the first instruction
5971 of a source line. This prevents the multiple stops that used to occur
5972 in switch statements, for-loops, etc. `Step' continues to stop if a
5973 function that has debugging information is called within the line.
5977 Lots of small bugs fixed. More remain.
5979 * New host supported (not target)
5981 Intel 386 PC clone running Mach i386-none-mach
5984 *** Changes in GDB-4.1:
5986 * Multiple source language support
5988 GDB now has internal scaffolding to handle several source languages.
5989 It determines the type of each source file from its filename extension,
5990 and will switch expression parsing and number formatting to match the
5991 language of the function in the currently selected stack frame.
5992 You can also specifically set the language to be used, with
5993 `set language c' or `set language modula-2'.
5997 GDB now has preliminary support for the GNU Modula-2 compiler,
5998 currently under development at the State University of New York at
5999 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6000 continue through the fall of 1991 and into 1992.
6002 Other Modula-2 compilers are currently not supported, and attempting to
6003 debug programs compiled with them will likely result in an error as the
6004 symbol table is read. Feel free to work on it, though!
6006 There are hooks in GDB for strict type checking and range checking,
6007 in the `Modula-2 philosophy', but they do not currently work.
6011 GDB can now write to executable and core files (e.g. patch
6012 a variable's value). You must turn this switch on, specify
6013 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6014 by assigning a new value to a variable. Modifications take
6017 * Automatic SunOS shared library reading
6019 When you run your program, GDB automatically determines where its
6020 shared libraries (if any) have been loaded, and reads their symbols.
6021 The `share' command is no longer needed. This also works when
6022 examining core files.
6026 You can specify the number of lines that the `list' command shows.
6029 * New machines supported (host and target)
6031 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6032 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6033 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6035 * New hosts supported (not targets)
6037 IBM RT/PC: romp-ibm-aix or rtpc
6039 * New targets supported (not hosts)
6041 AMD 29000 embedded with COFF a29k-none-coff
6042 AMD 29000 embedded with a.out a29k-none-aout
6043 Ultracomputer remote kernel debug a29k-nyu-kern
6045 * New remote interfaces
6051 *** Changes in GDB-4.0:
6055 Wide output is wrapped at good places to make the output more readable.
6057 Gdb now supports cross-debugging from a host machine of one type to a
6058 target machine of another type. Communication with the target system
6059 is over serial lines. The ``target'' command handles connecting to the
6060 remote system; the ``load'' command will download a program into the
6061 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6062 also supports debugging of realtime processes running under VxWorks,
6063 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6064 stub on the target system.
6066 New CPUs supported include the AMD 29000 and Intel 960.
6068 GDB now reads object files and symbol tables via a ``binary file''
6069 library, which allows a single copy of GDB to debug programs of multiple
6070 object file types such as a.out and coff.
6072 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6073 refcard.dvi and refcard.ps are available to format it).
6076 * Control-Variable user interface simplified
6078 All variables that control the operation of the debugger can be set
6079 by the ``set'' command, and displayed by the ``show'' command.
6081 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6082 ``Show prompt'' produces the response:
6083 Gdb's prompt is new-gdb=>.
6085 What follows are the NEW set commands. The command ``help set'' will
6086 print a complete list of old and new set commands. ``help set FOO''
6087 will give a longer description of the variable FOO. ``show'' will show
6088 all of the variable descriptions and their current settings.
6090 confirm on/off: Enables warning questions for operations that are
6091 hard to recover from, e.g. rerunning the program while
6092 it is already running. Default is ON.
6094 editing on/off: Enables EMACS style command line editing
6095 of input. Previous lines can be recalled with
6096 control-P, the current line can be edited with control-B,
6097 you can search for commands with control-R, etc.
6100 history filename NAME: NAME is where the gdb command history
6101 will be stored. The default is .gdb_history,
6102 or the value of the environment variable
6105 history size N: The size, in commands, of the command history. The
6106 default is 256, or the value of the environment variable
6109 history save on/off: If this value is set to ON, the history file will
6110 be saved after exiting gdb. If set to OFF, the
6111 file will not be saved. The default is OFF.
6113 history expansion on/off: If this value is set to ON, then csh-like
6114 history expansion will be performed on
6115 command line input. The default is OFF.
6117 radix N: Sets the default radix for input and output. It can be set
6118 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6119 in the current radix, so "set radix 10" is always a no-op.
6121 height N: This integer value is the number of lines on a page. Default
6122 is 24, the current `stty rows'' setting, or the ``li#''
6123 setting from the termcap entry matching the environment
6126 width N: This integer value is the number of characters on a line.
6127 Default is 80, the current `stty cols'' setting, or the ``co#''
6128 setting from the termcap entry matching the environment
6131 Note: ``set screensize'' is obsolete. Use ``set height'' and
6132 ``set width'' instead.
6134 print address on/off: Print memory addresses in various command displays,
6135 such as stack traces and structure values. Gdb looks
6136 more ``symbolic'' if you turn this off; it looks more
6137 ``machine level'' with it on. Default is ON.
6139 print array on/off: Prettyprint arrays. New convenient format! Default
6142 print demangle on/off: Print C++ symbols in "source" form if on,
6145 print asm-demangle on/off: Same, for assembler level printouts
6148 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6151 * Support for Epoch Environment.
6153 The epoch environment is a version of Emacs v18 with windowing. One
6154 new command, ``inspect'', is identical to ``print'', except that if you
6155 are running in the epoch environment, the value is printed in its own
6159 * Support for Shared Libraries
6161 GDB can now debug programs and core files that use SunOS shared libraries.
6162 Symbols from a shared library cannot be referenced
6163 before the shared library has been linked with the program (this
6164 happens after you type ``run'' and before the function main() is entered).
6165 At any time after this linking (including when examining core files
6166 from dynamically linked programs), gdb reads the symbols from each
6167 shared library when you type the ``sharedlibrary'' command.
6168 It can be abbreviated ``share''.
6170 sharedlibrary REGEXP: Load shared object library symbols for files
6171 matching a unix regular expression. No argument
6172 indicates to load symbols for all shared libraries.
6174 info sharedlibrary: Status of loaded shared libraries.
6179 A watchpoint stops execution of a program whenever the value of an
6180 expression changes. Checking for this slows down execution
6181 tremendously whenever you are in the scope of the expression, but is
6182 quite useful for catching tough ``bit-spreader'' or pointer misuse
6183 problems. Some machines such as the 386 have hardware for doing this
6184 more quickly, and future versions of gdb will use this hardware.
6186 watch EXP: Set a watchpoint (breakpoint) for an expression.
6188 info watchpoints: Information about your watchpoints.
6190 delete N: Deletes watchpoint number N (same as breakpoints).
6191 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6192 enable N: Re-enables watchpoint number N (same as breakpoints).
6195 * C++ multiple inheritance
6197 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6200 * C++ exception handling
6202 Gdb now supports limited C++ exception handling. Besides the existing
6203 ability to breakpoint on an exception handler, gdb can breakpoint on
6204 the raising of an exception (before the stack is peeled back to the
6207 catch FOO: If there is a FOO exception handler in the dynamic scope,
6208 set a breakpoint to catch exceptions which may be raised there.
6209 Multiple exceptions (``catch foo bar baz'') may be caught.
6211 info catch: Lists all exceptions which may be caught in the
6212 current stack frame.
6215 * Minor command changes
6217 The command ``call func (arg, arg, ...)'' now acts like the print
6218 command, except it does not print or save a value if the function's result
6219 is void. This is similar to dbx usage.
6221 The ``up'' and ``down'' commands now always print the frame they end up
6222 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6223 frames without printing.
6225 * New directory command
6227 'dir' now adds directories to the FRONT of the source search path.
6228 The path starts off empty. Source files that contain debug information
6229 about the directory in which they were compiled can be found even
6230 with an empty path; Sun CC and GCC include this information. If GDB can't
6231 find your source file in the current directory, type "dir .".
6233 * Configuring GDB for compilation
6235 For normal use, type ``./configure host''. See README or gdb.texinfo
6238 GDB now handles cross debugging. If you are remotely debugging between
6239 two different machines, type ``./configure host -target=targ''.
6240 Host is the machine where GDB will run; targ is the machine
6241 where the program that you are debugging will run.